1. Matter Matter is anything that occupies space and has mass.
Mass is the amount of matter in an object.

2. States of Matter
1. Solid
2. Liquid
3. Gas
A. Solid State
tiny particles that cannot move away from each other and they could not flow.
Two Important Characteristics of Solid
1. Solids have a definite shape
2. Solid have a definite volume

3. B. Liquid State
The particles are close but are not held as tightly together, free to move, and have no definite shape but has a definite volume.
The resistance of a liquid to flow slowly is called viscosity.
Ex: honey, rugby etc.

4. C. Gas State
It has no definite shape, volume, and the particles are very far apart from each other.

7. PROPERTIES OF MATTER
Properties:  Information about a substance that describe it and that helps us identify it. Characteristic Physical Properties - are physical properties that can be used to identify a substance because they never change.  Example: The density of water is always 1.00 g/mL at room temperature.

8. Solid State Examples: rubber, iron, ice, chalk
States of Matter
Particles of solids are held in place by strong electrostatic forces and are densely packed together. Particles of solids vibrate constantly due to their internal energy but they cannot move from one place to another.  Particles of solids possess only vibrational energy.
Solid State Examples:  rubber, iron, ice, chalk
Particles of a typical solid

9. Liquid State: Examples: alcohol, gasoline, oil, water
Particles of liquids are kept together by forces of attraction that are weaker than those of solid particles.  Within the walls of the  container they can move from place to place bumping into the sides of the container and into other particles.  This type of energy is called translational    energy.  Th is energy gives a liquid  the ability to flow and be poured and to spread when a liquid is spilled.  Liquid particles also have vibrational energy.
Particles of a typical liquid  (What could the two different types of particles indicate

10. Gaseous State: Examples: air, natural gas, carbon dioxide, steam
Particles of gases are "more rarefied" than either liquids or solids.  This means that the forces of attraction that hold them together are very weak and that the spaces between them are much larger than the spaces between solid and liquid particles. Particles of gases can move  from  place to place within a container bumping against the walls of  the container and against other particles. They rotate and vibrate at the same time.  Particles of gases have rotational, translational and vibrational energy.  This explains why they can escape from a container very easily and they can put pressure on the side of the container (example a balloon or a tire).
Brownian Motion demonstrating possible motion of tiny solids particles suspended in air (a gas) and indirectly showing the motion of particles of gases.

11. Physical Properties of Each State:
PROPERTY
SOLID
LIQUID
GAS
shape
fixed
same as container (indefinite)
volume
definite
fills entire container (indefinite)
ability to flow no
yes
can be compressed
very slightly
volume change with heating
very small
small
large

15. Two Properties of Matter
1. Physical Change
Characteristic of a substance that can be observed without changing the identity/composition of the substance.
Ex: mass, weight, density, volume, and phase.

16. Physical Change can happen if you cut, grind, bend, break, split, crack or crush a material.
When a substance undergoes physical change, it’s molecular
composition remains the same. This means that the substance does not lose its chemical identity, no chemical reaction occurs, and no other substance is formed.

17. Role of Temperature in Physical Change
1. Melting – a physical change wherein a solid turns into a liquid.
Ice + heat liquid water
When ice absorbs sufficient heat, it changes to a liquid. As ice absorbs more and more heat , its molecules move faster and faster until it has sufficient energy to overcome their rigid positions.

18. 2. Freezing – a physical change wherein a liquid turns into a solid.
Water – Heat Ice
Lowering the temperature makes the movement of water molecules slow down. When water gets cold, the molecules slow down. The spaces between molecules become bigger and the attraction becomes greater enough to freeze it into solid ice.

19. 3. Evaporation – a physical change wherein liquid turns to gas.
Liquid water + heat steam boiling temp.)
water vapor lower temp.)
Water turns to gas when its temperature is raised or when it is heated. No new substances is formed when liquid evaporates. As water is exposed under the sun, water absorbs heat. As water absorb more heat, its molecules move faster. They bump each other with a greater force and move away from each other thus, the space become bigger so, the attraction of molecules become weaker. The molecules at the surface of the liquid escape to the surrounding air as water vapor

20. Condensation – a process in which water vapor changes to a liquid.
Water vapor or steam – heat liquid water
Have you observed some water droplets outside a glass filled with ice and water? These water droplets are formed by condensation. The droplets outside the glass did not come from the water inside the glass. The droplets are formed when surrounding air molecules slow down. When they come in contact with the cold wall of glass, the gaseous molecules change into their liquid form. A low temperature is necessary in order condensation to take place.

21. Drying –removal of moisture, or drying, is a physical change
Drying –removal of moisture, or drying, is a physical change. Pressing forces out the moisture from the flowers, leaves or weeds. The sheets of newspaper absorb the moisture from the materials.

22. Another example of PC
Physical changes include any alteration or changes in the shape, size of a substance.
Example: breaking, cutting, slicing, grinding, crushing, dissolving.
Dissolving of sugar
Slicing of potato
Grinding of pepper

23. Physical & Chemical Changes
Physical Change
Chemical Change
Definition
No new substance is produced
Substance remains the same even with a change of state
May require addition of energy
 Release of energy may occur
Final substance is substantially different than initial substance
New substance is always produced
Energy is usually released but may be required to get the change going
Properties
Outside may look different
Inside remains the same
Particles may be rearranged
Forces of attraction between particles may be weaker or stronger
A new substance is produced
The particles of the new substance do not resemble those of the old substance
Internally, the substance produced is different than the old substances
Examples
Mixing sugar and water
Ice melts into water
Solid wax  ==>    Liquid wax
Vinegar and baking soda mix to form carbon dioxide
Hydrochloric acid reacts with magnesium metal to form hydrogen gas

24. 2. Chemical change
A substance ability to change into a different substance.

25. Meaning: A chemical change alters the materials composition
Meaning: A chemical change alters the materials composition . A substance that undergoes a chemical change loses its original properties and acquires a new set of properties. (Forming new substance)

28. Example: Hydrogen + Oxygen Water
A chemical change occur s when one or more substances (the reactants) change into one or more new substances (the products )
Example: Hydrogen + Oxygen Water
Heat
In this example, hydrogen gas burns in air. When ignited, hydrogen combines with oxygen in the air, forming water.
The reactants are hydrogen and oxygen and the product is water

29. Why hydrogen not use in balloons?

30. Burning of paper, burning of wood
In this example, wood burns in air. When ignited, wood reacts with oxygen in the air, forming carbon dioxide gas and water vapor, and leaving behind ashes from the wood. In addition, the reaction releases energy in the form of heat and light. That is why wood is often used as fuel for cooking.
Wood + Oxygen Carbon dioxide + ashes/charcoal + heat and light
Question : Burning of wood is a concrete example of chemical change, What do you think if more and more people will burn organic materials like wood, dry leaves and household waste and forest fires will continue to happen, what will happen to the planet earth?

31. Another example of chemical change
Rusting of iron – formation of rust, iron reacts with oxygen and water, forming rust (ferric oxide). Rust can destroy iron that is why iron products are coated with paint to prevent formation of rust.
Spoiling of rice
Tarnishing of silver
Souring of milk
Contaminated household waste
Rotting of fruits

33. Another example of chemical change
Rusting of iron – formation of rust, iron reacts with oxygen and water, forming rust (ferric oxide). Rust can destroy iron that is why iron products are coated with paint to prevent formation of rust.
Spoiling of rice
Tarnishing of silver
Souring of milk
Contaminated household waste
Rotting of fruits

34. Activity Observing Physical and Chemical Changes in Matter
Problem
How does Matter change its state?
What to do:
Draw/illustrate both physical and chemical changes(at least 5 examples for each changes) and explain or discuss how does matter change it’s state in your output.
You can apply and use different process applied in your activity.

35. .       General Properties of Matter
Intensive Properties: properties that do not depend on the amount of matter.  Some examples are:  color, odor, density, melting point
Extensive Properties: properties that do depend on the amount of matter.  Some examples are:  mass and volume

36. Intensive properties refer to properties that are independent compared to the size or quantity of the substance. These properties do not change when more of a substance is added or some of the substance is removed. Intensive properties include: density, color, viscosity, electrical resistivity, spectral absorption, hardness, melting point/boiling point, pressure, ductility, elasticity, malleability, magnetization, concentration, temperature and magnetic field.
These properties do not change if the size of the quantity of the substance changes. For example: the hardness of a diamond does not change, no matter how many times the diamond is cut. The color of the salt does not change no matter how much of it is added to the original amount. These all describe the intensive properties of the diamond and salt.

37. Extensive properties refer to properties that are dependent on the size or quantity of the substance. These properties change depending on how much of the substance is added or removed. The value of the additive property is proportional to the size of the system. For example if the size is increased, then the property will also increase. Extensive properties include: energy, mass, length, particle number, number of moles, volume, magnetic moment, weight and electrical charge.

38. These properties are directly proportional to the size and the quantity of the substance. For example: if the amount of water increases, the weight of the water will also increase; the more the water, the heavier it will be. Another example: the energy it would take to melt an ice cube is proportional to its size. The energy it would take to melt and ice cube differs from the energy that would be required to melt an iceberg.

39. How to Describe Matter (Qualitative & Quantitative Observations)
1.  Physical State : solid, liquid, gas.
2.  Color :              green, blue, yellow, black,
reddish-brown, etc.
3.  Odor (scent,smell):               odorless, flowery, spicy,
nauseating, offensive,
pleasant, fresh, stale. foul
 4.  Clarity :              clear, cloudy, opaque.

40.    5.  Luster :             shiny, dull.
   6.  Form :                 regular (crystalline), irregular
(amorphous)
   7.  Texture :              how  does it feel?  fine, coarse,
smooth, waxy, etc.
  8.  Hardness:         can it be scratched easily?  scale from
1-10                                           (e.g. talcum powder-1, diamond-10)
  9.  Brittleness:        can it break apart or shatter
easily?  brittle or flexible
10.  Malleability:    can it be bent and folded into different
shapes?  malleable or non-malleable
flattened into thin sheet
11.  Ductility:          can it be stretched out into a long
wire?  ductile or non-ductile
12.  Viscosity:  can the substance flow?  viscous or
non-viscous

44. Elements, Compounds & Mixtures
1.Consists of only one kind of atom,
2.Cannot be broken down into a simpler type of matter by either physical or chemical means, and
3. Can exist as either atoms (e.g. argon) or molecules (e.g., nitrogen).
1. Consists of atoms of two or more different elements bound together,
2. Can be broken down into a simpler type of matter (elements) by chemical means (but not by physical means),
3.Has properties that are different from its component elements, and
always contains the same ratio of its component atoms.
1. Consists of two or more different elements and/or compounds physically intermingled,
2. Can be separated into its components by physical means, and
3. Often retains many of the properties of its components.

45. This classification depends upon how we try and separate matter into its basic components. This separation is called the "process". There are two processes: a physical and a chemical process.
Physical process:
 a process using physical properties
Chemical process:
 a process using chemical properties
If we have a sample of matter and can find a physical process such as evaporation, magnets, color etc. to separate it then the sample is a "mixture". Furthermore if the sample is a mixture of solids and liquids (e.g., sand and water) etc. or two or more liquids that don't mix (e.g., oil and vinegar) then the mixture is "inhomogeneous/heterogeneous". Otherwise the sample is a "homogeneous" mixture.
If there is no physical process that will separate the sample then the sample is a "pure" substance. If a chemical process such as combustion or oxidation breaks the substance down to its constituent atoms then the substance is a "compound"(e.g., salt, sugar, water). Otherwise the substance is an "element" (e.g., copper penny, aluminum foil). Compounds are made up of molecules or salts. Elements are made up of single types of atoms.

47. Heterogeneous and homogeneous refer to mixtures of materials in chemistry. The difference between heterogeneous and homogeneous mixtures is the degree at which the materials are mixed together.
A homogeneous mixture is a mixture where the components that make up the mixture are uniformly distributed throughout the mixture. Example: air, blood, saturated sugar water A heterogeneous mixture is a mixture where the components of the mixture are not uniform or have localized regions with different properties. Example: oil and water, soup, pizza

54. Force and Motion A force is usually considered as a push and pull.
Forces can move, slow down, speed up or stop the motion of an object.
It can change body’s direction or even change it’s shape
Example of Applying Force
1. Torsion – if a force twist an object it is called torsion.
example – Physical therapist applies twisting or kneading pressure on the muscles during massage.
2. Tension – the force that stretches an object
Example – when a rope or rubber band is being stretched.

55. Types of Forces 1. Contact Force
A. Frictional Force or friction is the force exerted by a surface as an object moves across it. This force opposes the motion of an object.
Example: If a bag is being dragged across the floor, the floor exerts a frictional force in a direction opposite to the motion of the bag. Friction results from two surfaces that are in contact (touching) with each other.
Types of Friction
A. Rolling Friction – is the frictional force associated with the rotational movement of a wheel or other circular objects along a surface. Ex: Roller skates, skateboards, motor vehicle tires

56. B. Sliding Friction – also called as dry friction
B. Sliding Friction – also called as dry friction. Occurs when two objects rub against each other. It is cause by a chemical bonding between surfaces. When you move the block of wood on sandpaper, the movement of the wood is affected. The block of wood move slowly, with more force needed to move it.
C. Static Friction – it occurs in a stationary objects. It prevents an object from moving against a surface. If you push a table at rest on a table at rest on a floor but it does not move, then the force you applied is not enough to overcome the static friction between the table legs and the floor.
D. Applied Friction – is a force directed to an object by a person or another object. If the person pushes his ice cream cart along the road, there’s a force applied acting on the cart.

57. 2. Noncontact Forces
1. Gravitational Forces – is the reason why we kept on place here on Earth because gravitational force gives us our weight.
The force of gravity is always equal to the weight of the object as found in the equation.
W=mg
W- is the weight in Newton (N)
g – is the acceleration due to gravity that has a value of 9.8 m/s
m – is the mass of the object in Kg

58. Sample Problem: Weight on Earth
1. An object has a mass of 4.00 Kg. What is its weight?
Solution:
Given;
m = 4.00 Kg W=?
Formula: W = (m)(g)
= (4.00 Kg) (9.8 m/s)
= 39.2 kg-m/s or 39.2 N

59. Weight on Moon
However, our weight on earth is less than our weight on the moon because lunar gravitational force is less than Earth. Our weight on the moon is just one-six of our weight on earth.
Sample Problem
1. m= 39.2 Kg W=?
Formula : (1/6) (m)
= ( 1/6 ) (39.2 Kg)
= N

60. Complete the Table: Object Mass Weight on Earth Weight on Moon 1. Book
1.00 kg
2. Pomelo
12.0 N
3. Bag
3.66 N
4. Ruler
.58 kg
5. Frame
15.0 N

61. The weight of your science teacher is 490 N. Find his/her mass.
Another example:
The weight of your science teacher is 490 N. Find his/her mass.
Solution: W = 490 N
W = mg m = ?
W = mg N
g g m/s
m = W
= 50 kg g

62. Electromagnetic Force – it combines electrical and magnetic fields from the interactions of charged particles. It is more than a billion times stronger than gravitational force because it works at an infinite range. Example : TV and integrated circuits.
Nuclear Force – the force that holds the protons and the neutrons within the nucleus. This force prevents the mutual repulsion between positively charged proton from causing them to fly apart. It is considered a strong force that acts only on badrons (the proton and neutrons inside the nucleus) Because the strong force binds nuclear particles so tightly together, huge amount of energy are released when the elements fuse together, this process called nuclear fusion.
Example - atomic bomb that destroy Hiroshima is a product of nuclear fusion reaction.

63. MOTION
IS A CHANGE IN POSITION OF AN OBJECT WITH RESPECT TO A FIXED REFERENCE POINT.
Motion – can be described through its speed or fast or slow.
Variable Representations
V – speed
V – velocity
d – distance
d – displacement
a – acceleration
t- time

64. Speed
Speed – is the distance travelled by an object in a given amount of time.
Example 40 km/h
To calculate speed, consider the following combinations of units for distance with respects to time:
Kilometers per hour (Km/h)
Centimeter per second (cm/s)
Meter per second (m/s)
Centimeters per day (cm/day)

65. To compute speed: S = distance S = d ------------ ---- time t
time t
Sample problem:
1. Find the speed of the Tortoise if it took five hours to travel a distance of three kilometers.
Solution
Given: d = 3km Required
t = 5 h v = ?
V= d/t
= 3km/5h
V = 0.6 km/h

66. d = vt To solve the distance : Distance = speed x time
To solve for time :
Time = distance /speed
t= d/v
Do the Speed triangle

67. Solve for the missing variables:
V (m/s)
t (s)
d (m)
40 m/s
40 s
50 s
140 m
23.6
830 m
67 s
480 m 35
89 s

68. Activity No. 2 Exercises:
1. If Cathy, Myra, and Eva take 2.0 h to walk to their school at a rate of 1.0 m/s, how far is their school from their houses?
2. Sylvester, a smart and swift daschund, was able to catch his prey that was 8.5 m away in 1.8 s. What was Sylvester’s speed?
3. Tommy loves taking care of homing pigeons. He sent a note to his crush who lives 24.0 km. away from his home. These birds fly at a rate of 48.2 km/h. How long will the note reach Tommy’s crush?
4.The Cheetah, considered the fastest land animal, can travel 625 m in 25.0 s. What is its average speed?

69. 5. How far can the Cheetah in the previous problem go in one minute?
6. How long will it take the Cheetah to run a distance of 5.0 km if it runs at a speed of 25 m/s?
7. A truck’s speed increases from 12 m/s to 35 m/s in 30 s in one direction. Find the (a) magnitude acceleration and (b) the distance of a truck.
8. A Cebu Pacific plane bound for Kuala Lumpur, Malaysia accelerates on a runway from rest to 3.22 m/s for 32 s until it finally takes off. Find the distance traveled before take off.

70. 9. Michael Schumacher accelerates his race car uniformly from 18
9. Michael Schumacher accelerates his race car uniformly from 18.2 m/s to 48.2 m/s in 2.45 s. Determine the magnitude of acceleration of his car and the distance traveled.
10. Find the magnitude of acceleration of a jeep that is initially moving at 18 m/s and comes to a complete stop in 4.2 s.
11. A motor cycle accelerates from 36 km/h to 90 km/h in 10 s. Find the acceleration of the motorcycle and the distance travelled in this time.

71. Velocity
Velocity (v) is similar to speed except that is not only tells how fast or how slow motion is; it also indicates the direction.
Is a speed in a given direction
is a vector quantity. Vector quantities are described using both magnitude and direction.
Velocity tells us how fast a body moves and where it is going.
Example – The storm moving 80 kph due Samar
Displacement (d ) – indicates both distance and the direction of motion. It tells us how far and where you are from the starting point. It is possible for a sprinter to cover a distance of 100 m and have a displacement of zero?

72. Velocity of an object changes when
1. the speed changes
2. the direction of an object
3. both speed and the direction changes

73. Example :
1. A lady sprinter begins at point A and runs a distance of 700m around an oval and returns to point A again. What is the distance traveled? What is her displacement?
Given:
d = 700 m

74. Sample 2 : A Philippine Airlines plane regularly takes off from Manila at 5:30 am and is expected to land in Zamboanga, 852 km South of Manila, at exactly 7:00 am. What should the average velocity of the plane be if it is to land in Zamboanga City on time? Solution: Given: d = 852 km, South t = 1 hr and 30 min or 1.5 h v = displacement total travel time = 852 km h = 568 km/h, South

75. Acceleration
Acceleration is the rate of change of velocity and is measured in meters per second squared (m/s2) or centimeters per second squared (cm/s2)
Accelerating objects change their velocity by constant amount each second (constant acceleration) or by varying amounts each second (nonconstant acceleration)
Time (s)
Velocity (m/s) 1 2 3 4 5 6 8 12
Time (s)
Velocity (m/s) 1 2 3 4 5 7 10

76. Example: A car is accelerating if the speed increases or the gas pedal is pressed. A car is decelerating when the speed decreases or the car brakes are used. The acceleration of a car moving at a constant speed is equal to zero because there is no change in speed.
Acceleration is the change in velocity per unit time, then the change in velocity is the final velocity minus the initial velocity.
Formula :
Acceleration = Change in velocity
time
Where : a = acceleration
v f = final velocity
v i = initial velocity
t = time

77. Sample Problem:
1. Martin rides a bicycle at 1.5 m/s South. Ten seconds later, he is driving at 3.0 m/s South. What is Martin’s acceleration?
Solution
Given:
V i = 1.5 m/s Required
V f = 3.0 m/s a = ? D = ?
t = 10
a = v f – v i a = 30 m/s – 1.5 m/s
t 10 s
a = 1.5 m/s South
d = vt
= (1.5 m/s) (10 s)
= 15 m

78. Problem 2:
Calculate the acceleration of car at rest, then travel at 24 m/s due East in 30 s.
Solution:
Given : v i = 0 Required
v f = 24 m/s a = ?
t = 30 s
a = v f – v i t
a = 24 m/s -0 m/s
30 s
a = 0.80 m/s

79. Practice Exercises: Activity
1. A truck’s speed increases from 12 m/s to 35 m/s in 30 s in one direction. Find the (a) magnitude acceleration and (b) the distance of a truck.
2. A Cebu Pacific plane bound for Kuala Lumpur, Malaysia accelerates on a runway from rest to 3.22 m/s for 32 s until it finally takes off. Find the distance traveled before take off.
3. Michael Schumacher accelerates his race car uniformly from 18.2 m/s to 48.2 m/s in 2.45 s. Determine the magnitude of acceleration of his car and the distance traveled.
4. Find the magnitude of acceleration of a jeep that is initially moving at 18 m/s and comes to a complete stop in 4.2 s.
5. A motor cycle accelerates from 36 km/h to 90 kim/h in 10 s. Find the acceleration of the motorcycle and the distance travelled in this time.

80. Newton’s Three Laws of Motion
1. Law of Inertia
2. Law of Acceleration
3. Law of Interaction

81. 1. Law of Inertia – An object at rest tends to remain at rest
1. Law of Inertia – An object at rest tends to remain at rest. If in motion, it will tend to move at constant speed in a straight line unless it is acted upon by an unbalanced external force.
Inertia – a term used by Galileo to describe the tendency of an object to resist changes in motion.
Mass = a measure of inertia (mass dictates inertia)
Application of the first law
1. A book on the table will remain at rest if nothing disturb it .
2. A rolling ball will continue to roll at constant speed and direction if it is not disturb at all.
3. You tend to keep on moving whenever the bus slows down. On the other hand, you move back when bus makes a sudden start.
4. If you jump off a moving bus, you must run to keep from falling down.
Seat belts exert force that keeps you from moving forward.

82. Second law Law of acceleration
A n object’s acceleration is directly proportional to the net force acting on it and is inversely proportional to the object mass. The object always accelerates in the direction of the net force.
This means that the bigger the net force, the greater the acceleration; the smaller the net force, the slower the acceleration for bodies of constant mass. However, the bigger the mass the slower the acceleration; the smaller the mass, the greater the acceleration, if the force applied is the same.

83. The law of acceleration is mathematically express as:
Force = mass x acceleration
F = (m) (a)
Sample Problem:
1. How much force is needed to accelerate a 5 kg mass at a rate of 2 m/s ?
Solution:
Given:
m = 5 kg required
a = 2 m/s F = ?
= (5 kg) (2 m/s)
= 10 N

84. 2. At what rate will a 95 kg body accelerate if a force of 25 N is exerted on it?
Given: m = 95 kg Required
F = 25 N a = ?
a = F
----- m
a = 25 N
95 kg
a = m/s

85. Third Law Law of Interaction
In every action, there is an equal and opposite reaction
Example :
1. Recoiling of gun
2. releasing an inflated balloon
Application of the third law
1. When you push the wall, the action force is exerted on the wall. The reaction force is exerted on you.
Walking involved action and reaction force. You push the ground (action force) and the ground pushes you forward (reaction force)

86. Activity # 3
Applying Concept
Read each given situation. Apply the concept you learned to answer each question.
1. A ball is hit hard against a concrete wall. Use Newton’s third law of motion to explain what happens and why?
2. Ferris wheel in motion is moving in a circle. What force is acting on the Ferris wheel turning around. If force is removed, what will happen to the Ferris wheel?
3. A skydiver jump from the plane quickly falls towards the ground. When he open his parachute, he will slow down, Explain the forces that are acting on the skydiver and the parachute.

87. 4. You need Ketchup to spice up your hotdog, but it does not flow out of the bottle. Turn the ketchup bottle upside down, shake at high speeds and abrupt halt. That should do the tricks!
5. Taking the elevator from the eight floor to the ground floor, you experience blood rushing from your head to tour feet when the elevator quickly stops.
6. While riding a skateboard , you hit a stone, abruptly halting the motion of the skateboard and making you fly off the board.
7. A frog carefully pushes its hind legs backward to give it a forceful thrust forward as it swims through the pond.
8. Bump car riders experience a change in direction upon collision with other bump cars.
9. Birds fly by flapping their wings down, but the wind beneath their wings keep them up.
10. The damaging effect of a collision between a car and a truck will be greater in the car.

88. WORK
Defined as:
--- a force acting upon an object to cause a displacement. In order for a force to qualify as having done work on an object, there must be a displacement and the force must cause the displacement. (If a force causes an object to change its state, so there is a work being done)

89. Work = Force x Distance
W = Fd
Unit : Joule = Newton –meter
J = N – m
Since force is measured in newtons (N) and displacement is measured in meter (m)
The formula will become :
work = force x distance
= (N) (m)
= Nm

90. Sample Problem:
How much work would be done if an object was pushed to a distance of 5 m using a force of 400 N?
W = Fd or W = Nm
= 400 N x 5 m
= 2000 Nm
If it is required with a gravity:
Formula :
w = mgd

91. If it is required with a gravity:
Formula :
w = mgd
Problem:
How much work done on a 1.0kg object when you raise it to height of 3.0 m
Solution:
W = (1.0 kg) (9.8 m/s) ( 3.0 m)
= 29.4 Nm 29.4 joule

92. Solve the following :
1. Jun, whose mass is 62 kg, climbs a ladder that is 5.0 m high. How much work has Jun done?
2. Rick pushes 82 kg crate along 10 m distance. How much work is done?
3. How much force is needed to lift a 5.0 kg. backpack to a shelf 1.0 m above the floor?
4. An electric lift can raise a 500 kg mass and a distance of 10 m in 5 seconds. What is the power of the lift?

93. Machine
Machine – a device that helps man work more easy and efficiently.
Machine do work in three ways:
1. It can increase or multiply force
2. It can increase speed
3. It can change the direction of a force

94. Six Simple Machines
1. Lever
2. Inclined plane
3. Wheel and axle
4. Pulley
5. Wedge
6. Screw

95. Major Group of Simple Machines
1. Lever – pulley and wheel and axle are modified levers
2. Inclined Plane – wedge and screw are modified planes
Mechanical Advantages
With any machine, an effort is exerted to overcome some resistance. A small amount of this effort force can overcome a fairly large resistance. Therefore, a machine provides some mechanical advantage.
Mechanical Advantage (MA) = Resistance/load
Effort Force
The greater a machine mechanical advantage, the less force you have to exert to overcome the resistance .

96. Mechanical Advantage
Mechanical Advantage (MA) is the number of times a machine multiplies the force applied to it.
2 Types MA
1. Theoretical Mechanical Advantage (TMA)
2. Actual Mechanical Advantage (AMA)
TMA = distance effort moves (d E)
distance load moves (d R)

97. AMA – is the number of times the machine has actually helped in doing work.
AMA = force produced = load or resistance = R
force applied = effort E

98. SAMPLE PROBLEM:
1. A machine has a mechanical advantage of 5. If a balikbayan box weighing 1,000 N is to be lifted onto a truck, how much effort is needed?
Given : AMA = 5 R = 1,000 N E = ?
Formula : AMA = R
----- E
E = R E = 1,000 n
AMA
E = 200 N

99. The Lever
The lever is a rigid object that is free to move about a fixed point known as the fulcrum.
Three component of a lever
1. Fulcrum (F) – the point around which the lever rotates
2. Resistance (R) - the load or weight or force that must be lifted or supported; the distance between the resistance and the fulcrum is known as resistance arm (dr)
3. Effort force (E) – the force being exerted, the distance between the effort and the fulcrum is known as the effort arm.
Three Classes of Lever
1. First class lever – F in the middle (eg. Hammer)
2. Second class lever - R in the middle (eg. Nut cracker)
3. Third class lever – E in the middle (eg. Staple remover

100. First class Lever
It function as a force multiplier when the resistance is closer to the fulcrum than the effort. By placing the resistance is closer to the fulcrum or moving the effort force farther away, we can make effort force a small as possible.
Second class lever
The resistance is always nearer than the effort to the fulcrum in a second class lever. As with the first class lever, the closer the resistance is to the fulcrum, the smaller the force needed to lift it.
Third class lever
In the third class lever, the effort force is always closer to the fulcrum than the resistance. The third class lever is not a force multiplier like the first and second class. It is rather a distance multiplier. Greater force is exerted but the resistance moves through a greater distance.

101. Mechanical Advantage (MA) of a Lever
MA = Resistance = Effort Arm = d E =
Effort force Resistance arm d R
Solve the following :
1. Calculate the AMA of a pair of scissors if the force applied on the handle is 198 N and the resistance or load is 375 N
2. A street sweeper holds her 1.50 m long broom with one hand at 0.35 m from the fulcrum. Find the TMA.
3. Find the mechanical advantage of a baseball bat if the applied force is 240 N and the resistance is 550 N. Find the AMA

102. Pulley
Pulley is a groove wheel that is free to turn on an axle. The axle of a pulley does not turn with the wheel, it is used mainly to lift loads.
Example of where you found pulley in the are venetian blinds and flagpoles.

103. Pulley maybe:
1. Fixed pulley – it always provide a mechanical advantage of 1 because it serve to change the direction in which the force is exerted, rather than to supply a mechanical advantage. Pulley is attached to a fixed object and a rope is passed over the grooved wheel.
2. Movable pulley – provide a mechanical advantage equal to the number of strands or ropes attached to the load. Pulley is attached so that it moves with the resistance.
Mechanical Advantage of a Pulley
MA = number of sections of rope that support the resistance.

104. Wheel and Axle
Wheel and axle is a simple machine that is also very simple to describe. It is essentially a modified lever using two circles – a small and a big one. If effort is applied to the wheel, it turns the axle. The larger the wheel, the greater the forces are over the distance of the axle.
Examples: vehicle wheels, motorized fans, circular saws.
Other examples|: screwdrivers, roller skates, steering wheel of a car

105. Calculation of wheel and axle:
It is measured by means of Force produced and Force applied
TMA = diameter of the wheel
diameter of the axle or
TMA = radius of wheel
radius of axle
Sample problems:
A wheel has a diameter of 40 cm and is attached to an axle that has a diameter of 10 cm. What is the MA of this wheel and axle?
Solution : diameter of wheel = 40 cm Required = MA ?
diameter of axle = 10 cm
MA = 40 cm
10 cm
= 4

106. TMA = 3.0 Required = diameter of wheel? diameter of axle = 2.0 inches
2. The MA of the wheel and axle is 3 and the axle has a diameter of 2.0 inches. Find the diameter of wheel in cm.
Solution
TMA = Required = diameter of wheel?
diameter of axle = 2.0 inches
TMA = diameter of wheel
diameter of axle
diameter of wheel = TMA (diameter of axle)
= 3 (2.0 inches)
= 6.0 inches
Convert 6.0 inches to cm.
6.0 x 2.54 cm = cm
1 inch.

107. Examples: Stairs and escalator
Inclined Plane
- is a simple machine that consist of a ramp or sloped that joins two different levels. We use inclined plane so that less effort will be employed over a longer distance.
Examples: Stairs and escalator
The longer the distance an inclined plane covers, the easier it is to do the work.
The inclined planes can be determined using the following equations.
TMA = length of ramp
height of ramp
AMA = force produced = resistance or load
force applied effort

108. Sample Problem:
1. Mang Roger pushes a barrel with a weight of 5.00 N up a ramp
that in 6.00 m long and 3.00 m high. If it takes him 3.00 N of force to roll the barrel up the ramp, find (a) theoretical and (b) actual mechanical advantage and (c ) What is the efficiency of the inclined plane?
Given: load, L = 5.00 N
effort, E = 3.00 N
length, l = 6.00 m
height, h = 3.00 m
TMA = l = 6.00 m = 2.00
h m
AMA = R = 5 m = 1.67
E m
c. E = AMA x 100
TMA
= 1.67 X100
2.00
= 83.5 %

109. Wedge
is a simple machine with one slanted side. It is categorized as an inclined plane with a different function . It cuts materials apart or holds objects apart. An inclined plane also used while at rest, while a wedge moves to do its work. The sharps edges of a knife, scissors and chisel, nail, saw and can opener are wedges. In inclined plane the effort applied in a slant while wedge, the effort force is perpendicular to the direction of travel of the machine.