Motion Observing To observe an object in motion, you must use a referenced object. The one sitting still is considered to be the reference point. When an object changes position over time, compared to the reference point, the object is said to be in motion

When an object is at rest, what is its speed? 2 mph 1 mph 3 mph 0 mph

Motion is change in ____. speed velocity eyeliner position

A reference point for determining position and motion could be Cloud Building A moving object All of the above

Inertia is a function of mass. Chemistry Inertia Inertia is a function of mass. Inertia - tendency of an object to resist changes in its direction In other words an object stays at rest until something causes it to move Massive objects have large inertia Small objects have small inertia

Inertia Balanced force Gravity Drunk driver A person in a head-on car collision who is not wearing a seat belt continues to move forward at the original speed of the car because of ____. Inertia Balanced force Gravity Drunk driver

Which one of the following objects has the greatest inertia? pencil Bowling ball Baseball Your head

Motion Speed the rate at which an object moves two variables need to be considered a. distance b. time therefore: speed = distance time (s)

The distance traveled divided by the time it took to travel that distance determines an object's Acceleration Position Speed Force

The SI unit for speed is Km/foot feet/second meter/second mile/hour

Motion Average speed is a measure of the distance traveled in a given period of time; it is sometimes referred to as the distance per time ratio. Suppose that during your trip to school, you traveled a distance of 5 miles and the trip lasted 0.2 hours (12 minutes). The average speed of your car could be determined as

Motion Velocity the speed of an object in a particular direction For example: 15 m/s east or 22 m/s southwest velocity always includes which way; N, S, E or W

Velocity is determined by speed and direction True False

Motion Resultant velocity this calculation is determined as follows How fast is the boy moving? a. if velocity is in the same direction e.g. b. if velocity is in opposite directions e.g.

If a bus is traveling south at 15 mph and a boy stands and walks north at 1 mph what is the resultant velocity 15 mph 1 mph 14 mph 16 mph

If a bus is traveling south at 15 mph and a boy stands and walks south at 1 mph what is the resultant velocity 15 mph 1 mph 14 mph 16 mph

Motion Acceleration is the rate at which velocity changes to apply a force to an object to make it either slow-down, speed-up or change direction. To calculate acceleration: Acceleration = final velocity– starting velocity time it takes to change velocity (s) = mps s

Motion

100 mph/s 600 mph/s 60 mps/s 50 mph/s What is the acceleration of a dragster that goes from 0 to 300 mps in 5 seconds? 100 mph/s 600 mph/s 60 mps/s 50 mph/s

The acceleration of an object 1. Does not deal with force 2. is always opposite of the force that was applied. 3. is always in the same direction as the force. 4. None of the above

Acceleration of an object Slows down with increase in weight Increases with force Is in the same direction All of the above

Observe the animation of the three cars below. Which car or cars (red, green, and/or blue) are undergoing an acceleration? Study each car individually in order to determine the answer. Now that you've answered the first question correctly, try this one: which car (red, green, or blue) experiences the greatest acceleration? As a final test of your understanding, consider the position-time graph at the right. Each one of the three lines on the position-time graph corresponds to the motion of one of the three cars. Match the appropriate line to the particular color of car.

Motion Force either a push or a pull Unbalanced force produces a change in acceleration net force is greater than zero Balanced force produces no acceleration net force is zero

Motion Net force is the combination of 2 forces

A force is which one of these? Push Pull Push or Pull None of the above

When two birds are pulling on a worm and the worm moves toward the first bird, you know that the forces are ____. Balanced Unbalanced Action-reaction Unfair

Which of the following is NOT an example of a force being exerted? Pushing open a door Sitting in a chair Texting None of the above

Balanced forces applied to an object makes that object Stay at rest Change direction Accelerate Slows down

Gravity Balanced Friction Centipedal Unbalanced You have made a house of cards on top of your table. Suddenly, a gust of wind blows through an open window and your house of cards comes tumbling down. The wind applied ____ to your house of cards. Gravity Balanced Friction Centipedal Unbalanced

Motion Friction force that opposes motion between two surfaces that are touching hills and valleys Greater the force, greater the friction

The force that opposes motion Gravitational Balanced Unbalanced Friction

One way to increase friction is to use wax water sand oil

how? difference in force is canceled by the difference in mass Motion Gravity and Motion all objects fall to the ground at the same rate What would hit first, elephant or feather? how? difference in force is canceled by the difference in mass

Motion Air resistance slows down acceleration air resistance continues to increase until it matches the downward force of gravity object then falls at a constant velocity called terminal velocity

Motion Another example of terminal velocity Remember, the increase in air resistance continues till it is even with gravity

Motion Free fall no air resistance can only occur in a vacuum the only force acting is gravity

Motion Newton’s Laws of Motion Three laws that relate force to the motion of objects First law aka. law of inertia An object at rest tends to stay at rest and an object in motion tends to stay in motion with the same speed and in the same direction unless acted upon by an unbalanced force.  

Examples of Newton’s 1st Law

Newton’s first law of motion applies Moving objects No moving objects Speed Both 1 and 3 Countdown 10

Remain in motion Stop Blow up Accelerate According to Newton’s first law of motion, a moving object that is not acted on by an unbalanced force will Remain in motion Stop Blow up Accelerate Countdown 10

Newton’s first law of motion states that an object stays at rest unless a(n) ____ acts on it. Balanced force Gravitational force Unbalanced force Friction force Countdown 10

Motion Second Law due to unbalanced force that the acceleration of an object is dependent upon two variables a. the net force acting upon the object and b. the mass of the object

Examples of Newton’s 2nd Law

Motion Third Law that for every action (force) in nature, there is an equal and opposite reaction; force pairs in other words: if object A exerts a force on object B, then object B also exerts an equal force on object A note: we are only talking about forces

Examples of Newton’s 3rd Law

Motion Momentum property of a moving object that depends on the object’s mass and velocity in other words: more momentum an object has the harder it is to stop the object Conservation (constant) of momentum That is, the momentum lost by object 1 is equal to the momentum gained by object 2

Motion Energy the ability to do work remember, work is a transfer of energy so therefore work only occurs if the force and motion are in the same direction Work = F x d; force times distance since force is in Newtons (N) and distance is in meters the new label is J or Joules

Motion Energy of Motion called kinetic energy as long as an object is moving there is kinetic energy kinetic energy depends on mass and velocity creating work

Motion Energy of position called potential energy gravitational potential energy depends on weight and height tells us about stored energy that has the capacity to do work

Motion Mechanical energy kinetic energy + potential energy as the height decreases the PE also decreases as the speed increases so does the kinetic energy

Motion Types of energy

Motion Conservation of energy energy can be neither created nor destroyed total amount of energy in a closed system is always the same with conversion of energy you always get thermal energy what are the energies in the rollercoaster ride?

Motion Temperature temperature depends on the kinetic energy of the particles as a substance gets hotter, it’s particles moves faster

Motion Temperature conversion

Motion Heat transfer of energy between objects of different temperatures energy is transferred from higher temperatures to lower temperatures

Motion Types of energy transfer a. conduction – heat transfer by direct contact higher kinetic energy to lower kinetic energy b. convection – heat transfer by movement of liquid or gas c. radiation – heat transfer as electromagnetic waves