2What is motion?An object is in motion if its position changes relative to a reference pointReference point: place or object used for comparison to determine if something is in motion
3Motion is RelativeMotion is relative – it depends on where the reference point isYou may not be moving according to one reference point, but you may be moving according to another.Carousel – page 6
4Practice ProblemsJane is sitting in the family car. Her mother is driving her from their house to the library. Jane waves as she passes her friend Marina. Which of the following is not moving with respect to Jane?MarinaThe family carThe libraryJane’s house
5Practice ProblemsWhat is the best reference point for describing the motion of planets around the solar system?What is the best reference point for describing the motion of the moon around the Earth?
6Exploring Reference Points The reference point determines if the object seems to be still or be in motion. Ex: a crow is flying along carrying a ball. Suddenly, the crow accidentally drops the ball and watches it fall. A person is standing on the ground watching the crow and the ball.
7Exploring Reference Points If the crow is the reference point, in what direction is the ball falling?If the woman is the reference point, in what direction is the ball falling?
8Question to think about You are standing at your locker and your friend is walking towards.The next day, you see your friend walking towards you and you decide to start walking towards him too. To you, (as the reference point) does he seem to moving slower or faster than yesterday?
9Question to think about You are standing outside of school on the turnpike waiting for your ride home. The speed limit on the turnpike is 35 mi/hr. How fast are the cars moving passed you?Now you are in the car driving down the road (at the speed limit, of course) and you are passing cars along the way. How fast is YOUR car moving in relation to you? How fast are the other cars moving passed you?
10Which objects are in motion? Two trucks are heading towards each other, and there is a person standing still in between. Truck #1 is travelling at 30 mi/hr in the direction shown. Truck #2 is travelling at 20 mi/hr in the direction shown.According to the person, how fast are trucks 1 and 2 moving?According to truck 1, how fast is the person and truck 2 moving?According to truck 2, how fast is the person and truck 1 moving?
11Enriched Problem – try with a partner CC Sabathia throws a 90 mi/hr fast ball.CC is standing at the back of the Yankees bus that is traveling 60 mi/hr down the highway (going to beat the Red Sox).CC decides to begin warming up and throws a pitch from the back to the front of the bus.Brett Gardner, another Yankee, sees CC’s pitch as being how fast?If a fan standing on the side of the road saw CC’s pitch, how fast would they see it?
13What is speed?The speed of an object is the distance the object moves per unit of time (it is a type of rate)
14How to calculate speedSpeed is equal to the distance the object travels, divided by the amount of time it takes to travel that distance.Speed = distance ÷ time
15Steps to solve speed problems Read the entire problemWrite down what you are given (speed, distance, time)Write down what you need to find out (speed, distance, time)Draw the triangleCover the part of the triangle that you are looking forDivide or multiply to solve the problemWrite your answer with the correct units!
16Understanding the meaning of rates If a car is driving 10 miles per hour, how far has the car gone in one hour?If an airplane flies at 260 meters per second, how far has the plane gone in one second?
17Speed problemsA swimmer swam 6 km in 0.2 hours. What was the swimmer’s speed?A runner ran a 26 mile marathon in 5 hours. What was the runner’s speed?A police car chased a truck for 30 miles and it took 20 minutes. How fast was the police officer going?
18A bit more difficult…Odell Beckham Jr. runs at a speed of 7 km/hr. How long would it take him to run 400 kilometers assuming he does not get tired and slow down.McKayla Maroney (Olympic gymnast) runs 60 ft. at a speed of 15 ft/sec. How long does it take her to get to the vault?
19Even more difficult…A train leaves NYC and begins traveling 3,000 miles to L.A. The train drives at a constant speed of 80 mi/hr without stopping along the way. If the train leaves at 1 a.m. (eastern time), what time will is arrive in L.A. (eastern time)?After arriving in L.A., the train drops off passengers and begins traveling to Austin Texas. The train keeps the same speed (80mi/hr) and travels for 17.5 hours until it reaches its destination. How far is Austin from L.A.?
22What is velocity?The velocity of an object is the objects speed in a given direction.Ex:SpeedThe car is moving at 40 miles/hourThe girl is running at a speed of 5 km/hourVelocityThe car is moving north at a speed of 40 miles/hourThe storm is moving 25km/hr eastward
23How to calculate velocity Velocity is equal to the distance the object travels, divided by the amount of time it takes to travel that distance in a certain directionVelocity = distance ÷ time (in a certain direction)Solve same way you would solve speed problems (using velocity = to speed) and including direction in your answer!
24Practice ProblemsA flock of birds are flying 300 miles south for winter. It takes them 12.5 hours to reach their winter home. What is the speed of the flock of birds? What is the velocity of the flock or birds?
25Try to solve these with a partner Amber walked to talk to her friend Maria on her way to the pool. Amber walked 400 meters westward for four minutes until she met up with Maria.After talking with Maria for 3 minutes, Amber continued walking another 400 meters westward towards the pool for six more minutes.Identify all of the following:How far did Amber travel in total?How long did it take Amber to get to the pool?What was Amber’s velocity during each portion of the trip?
26Let’s think back to this problem CC Sabathia throws a 90 mi/hr fast ball.CC is standing at the back of the Yankees bus that is traveling north 60 mi/hr down the highway (going to beat the Red Sox).CC decides to begin warming up and throws a pitch from the back to the front of the bus.A fan standing on the side of the road saw CC’s pitch and clocked it as how fast? What was the velocity of his pitch?
27Let’s go a bit more in depth… The fan clocked CC’s pitch as traveling 150 mi/hr.Now, CC decided to stand in the front of the bus and throw towards the back so he would not distract the driver. The bus is till traveling north at 60 mi/hr and CC’s arm has yet to get tired (still throwing 90 mi/hr). Now what speed would the fan on the side of the road see? What would the velocity be?
28More practiceCar A travels EAST at an average speed of 20 miles per hour for 3 hours and then stops. Car B travels WEST at an average speed of 50 miles per hour for 2 hours and then stops. Both cars start from the same place. How far apart are the cars?Two tigers are hunting deer. The tigers start from the same place, but run in OPPOSITE directions to catch their own deer. Tiger #1 runs at an average speed of 30 miles per hour for 1 hour to track down his deer. Tiger #2 runs at an average speed of 20 miles per hour for 1 hour to catch its deer. How far apart are the tigers eating?
31What is acceleration?Acceleration – the rate at which velocity changesRefers to an increase in speed, a decrease in speed (deceleration), or a change in directionNote: a change in direction = a change in velocity
32Calculating acceleration Acceleration is the change in speed per unit of time.Acceleration = (final speed – initial speed) ÷ timeAcceleration = (24m/s – 0m/s) ÷ (3 sec)Acceleration of the plane = 8 m/s^2
33PracticeA racecar travels at 20 feet per second while they clear the track of an accident. When the race resumes, the car speeds up to 100 feet per second in exactly 5 seconds. What is the acceleration of the car?
34More Practice (watch your units!) A car advertisement says its car can go from a speed of zero to 80 miles per hour in a time of .001 hr! What is the acceleration of that car?Rock’N’ Rollercoaster in Disney World claims to go from 0 to mi/s in 2.8 seconds. What is the acceleration of the rollercoaster?
35Trip to the Cayman Islands You are taking a trip to the Cayman Islands. The airplane starts from rest (0 m/s) and speeds up to 65 m/s in 8 seconds. What is the plane’s acceleration?After a long flight, you are about to land on Grand Cayman! The plane is traveling at a speed of 72 m/s and safely lands and stops in 8.6 seconds. What is the deceleration of the plane?
36Trip to the Cayman Islands While on Grand Cayman, you and your family decide to go to an amusement park! You go on a rollercoaster that twists, turns, and flips.The rollercoaster increases to .016 mi/s in just 3 seconds. What is the acceleration of the rollercoaster?The rollercoaster stays at .016 mi/s throughout the entire ride until it is over. It takes 5.2 seconds to come to a complete stop. What is the deceleration of the rollercoaster?
37This may be tricky…Your rollercoaster accelerates to 57 mi/hr (at the beginning of the ride) and then continues at a constant speed. Does it accelerate in any way prior to the ride ending? Why or why not?
40What is a force? Force: a push or pull on an object Includes strength and direction (like velocity)The SI unit used to measure force = newton (N)
41Net Forces Net Force: combination of all forces acting on an object Determines if and howan object will accelerate
42Balanced and Unbalanced Forces Will NOT cause change in an object’s motionForces “cancel” each other outNet force = 0Will cause change in an object’s motionForces DO NOT “cancel” outNet force ≠ 0
43Free Body Diagrams (FBD) Draw a box to for the objectAdd arrows (for direction) with strength of all forces acting on object
44Let’s Try This Together Two dogs are pushing against their box of food. Using the picture to the right, draw a free body diagram. Then, determine the net force acting on the box of food.
45Try these with a partner Mrs. K’s car got stuck in the snow last week. When trying to get it out, she exerted a 23 N force on her car towards the left but it wouldn’t budge. Her husband started to help her and exerted an additional 27 N force towards the left on her car. Draw a FBD and determine the force it took the move Mrs. K’s car out from the snow.Mrs. Kopacz pulls on her dog’s leash to the right with an 18 N force. Her dog pulls to the left with a 8 N force. Draw a FBD and then determine the net force on the leash.
46Individual practiceMrs. Kopacz and Miss Aquino were playing tug o’ war over the weekend. Mrs. K pulled to the left with a 20 N force. Mrs. Aquino pulled to the right with a 23 N force. Draw a FBD and determine the net force acting on the rope. Who won tug o’ war? How do you know?
51Newton’s First Law of Motion Law of InertiaAn object at rest will remain at rest unless acted upon by an outside forceAn object in motion will stay in motion unless acted upon by an outside force
52Newton’s Second Law of Motion An object’s acceleration depends on its mass and the net force acting on itForce = mass x acceleration
53Calculating ForceF = maYou can use the triangle!A 10 kg box accelerated up the hill at 2 m/s². What force is exerted on the box?A 15 kg box is slid across the floor with an acceleration of 3m/s². What force is needed for this motion?
54Try to create your own force word problems! Then, trade with a partner and solve.
55Newton’s Third Law of Motion If one object exerts a force on another object, then the second object exerts a force of equal strength in the opposite direction on the first object.Many sports (including gymnastics) exemplify this law
56Newton’s 3rd Law of Motion While driving down the road, a firefly strikes the windshield of a bus and makes a quite obvious mess in front of the face of the driver. This is a clear case of Newton's third law of motion. The firefly hit the bus and the bus hits the firefly. Which of the two forces is greater: the force on the firefly or the force on the bus?
68Transverse waves: medium particles move across (up & down) the direction of the wave Crest: high point of waveTrough: low point of waveA water wave is an example of a transverse wave. As water particles move up and down, the water wave itself appears to move to the right or left
692. Longitudinal waves: medium particles move back and forth in the same direction in which the wave travels-Coils move forward and then backEnergy travels from one end of the spring to the other creating a wave-After the wave passes,each coil returns to theposition where it started
70Comparison of WavesWe will mainly discuss transverse waves
71Properties of transverse Waves - Crest = Top of the wave- Trough = Bottom of the wave- Wavelength = The length of a complete wave fromcrest-to-crest or trough-to-trough- Amplitude = Height of the wave from equilibrium
72Why does this matter? A smaller wavelength = higher energy Frequency: amount of waves per secondWaves on the electromagnetic spectrum all have DIFFERENT FREQUENCIES
79Vocabulary to knowTransparent: material that allows most or ALL light to pass through (clear)Translucent: material that allows SOME light to pass through (clear colored)Opaque: material that does NOT allow ANY light to pass through (all light is reflected or absorbed)
81rainbowsWhite light is not a single color; it is made up of a mixture of the seven colors of the rainbow.We can demonstrate this by splitting white light with a prism:How do you think rainbows are formed?
83How we see colorsThe colors that we see are REFLECTED off of the object – all other colors are ABSORBEDEx: a shirt appears light blue (reflects blue)The shirt absorbs other colorsEX: a shirt appears white (reflects white)
84reflection Reflection occurs when light bounces off a surface Light rays reflected in a mirror cause an inverted image
85refractionRefraction occurs when light BENDS as it crosses through material
88View kacleaveland's map Taken in a place with no name (See more photos or videos here)View kacleaveland's map"Have you ever approached a giant concave mirror? See your upside-down image suspended in mid-air. Walk through the image to see a new reflection, right-side-up and greatly magnified. In the background you see reflected a room full of visitors enjoying otherConcave MirrorsCurves inwardImages look bigger
89Convex Mirrors Curves outward Images look smaller Use: Rear view mirrors, store security…CAUTION! Objects are closer than they appear!
90Concave LensesLenses that are thicker at the edges and thinner in the center.Images look smaller
91Convex LensesThicker in the center than edges.Images look bigger
92The Human EyeThe human eye is a complex structure with many parts that allow you to see. Use the words in the word bank to identify the parts of the eye.
95What is electricity?Electricity is the flow of electrical power or charge.Electricity is a form of energy.Electricity is the flow of electrons.
96Static Electricity Transfer of charge from one object to another Rubbing your feet against the carpetRubbing a balloon against a sweater
97Lightning – Ultimate Static Discharge Thunderstorms have violent air currentsWater drops rub up against ice crystalsOne area of the cloud becomes negativeOne area of the cloud becomes positiveResult: STATIC DISCHARGEIf the bottom of the cloud gets enough of a negative charge, discharge can go from cloud to ground
99How does electricity get to your home? ElectromagnetismHow does electricity get to your home?
100Electromagnet Electricity in a wire produces a magnetic field If a piece of iron is wrapped around the wire, the iron becomes a temporary magnetDisconnect the powerThe magnetic field stopsThe iron loses magnetism quickly
101AC/DC Electricity from generators are “Alternating Current” It flows in two directions over and over againPower in your house is alternating currentYou can change ‘AC’ into ‘DC’Battery power is “Direct Current”It flows in one directionFrom one side of the battery to the other
102Transformers (NOT Robots in Disguise) When electricity leaves a generator, it needs a huge push to get to your house (Hundreds of miles away)Step-Up TransformerThe voltage is high, but it can only push so hard. The force needs to be increased if it is going to get from Niagara Falls to you.
103Step-Down Transformer The electricity gets to the sub- station near your home.It doesn’t need a big push anymore because it has a shorter distance to goToo much push from such a short distance could be too much for your house to handle (120 volts)Step-Down Transformer
104Electrical CircuitsIn order for electricity to go from one place to another, you need a “circuit”Electrical Circuit – A complete, unbroken path that electricity can flow from one place to another
105What are circuits made of? Conductors – A material through which electric current can pass easilyExamples:Any metal (especially copper)WaterInsulators – A material through which electricity cannot passUsed to cover wires so they can be handledRubberPlastic
106Circuit TerminologyCurrent = The amount of electrons flowing in a wireVoltage = The force that pushes electrons through a wireThe stronger the force, the more current gets pushed through the wireResistance = The force that reduces current in a wire.The stronger the resistance, the smaller the amount of current
107Circuit Terminology Current = amperes (amps) (A) Voltage = volts (V) Resistance = Ohms (Ω)
108Batteries Provide Voltage Filled with electrons Electrons are attracted to the positive terminal
109Ohm’s LawCurrent = Voltage divided by Resistance
110Practice ProblemsWhat is the current in a 1.5 Volt circuit that has a resistance of 3 Ohms?There is a current of .25 Amps in a circuit that has a voltage of 4.5 Volts. What is the resistance in this circuit?A circuit has a resistance of 6 Ohms and .5 Amps of current. What is the voltage of this circuit?
111Series CircuitThere is only ONE path for the electrons to get to the positive terminal
112Parallel CircuitMore than one way to get to the positive terminal
113Calculate PowerPower: rate at which energy transforms from one form to anotherPower = voltage x currentPower (kW)Voltage (V)Current (Amps)
114Paying for Electricity You pay for energy used, not power!Energy = power x timeEnergy (kWh)Power (kW)Time (h)When figuring out payments for electricity, find power, and then find energy used.