Upgrade to remove ads
Physics Chapter 3 test
Terms in this set (41)
The ____ states that the total amount of momentum in a closed system cannot change.
law of conservation and momentum
____ is calculated by multiplying a force and the time needed for the force to act.
According to ____, for every action force, there is a reaction force equal in strength and opposite in direction.
newton's third law
The mass of an object multiplied by its velocity equals its ____.
The ____ states that energy can never be created or destroyed, just changed from one form to another.
law of conservation of energy
The unit of energy needed to push with a force of one newton over a distance of one meter is one ____.
Energy due to position is known as ____.
Energy of motion is called ____.
____ is needed to cause change to an object, such as changing its speed or height.
____ is force times distance moved in the direction of the force.
When two or more objects hit each other, a ____ occurs.
When two objects collide and stick together or change shape, it is called a(n) ____.
Two billiard balls bouncing off each other is an example of a(n) ____.
State Newton's third law in your own words.
for every action force there is an equal and opposite reaction force
Action and reaction forces always have the _____ strength and act in _____ directions.
You and a friend are sitting across from each other on chairs with wheels. You push off each other and move in opposite directions. Explain the following:
1. How does the force you feel compare to the force your friend feels?
2. If your mass is greater than your friend's mass, how do your accelerations compare?
1. they are exactly the same but in opposite directions
2. because you have more mass than your friend, your acceleration is less than your friend's
A book rests on a table. The force of gravity pulls down on the book. What prevents the book from accelerating downward?
the table pushed up on the book with an equal and opposite force
Give an example of Newton's third law in everyday life. List the action and reaction forces in the example.
If I am on roller blades, I can push against a wall and the wall pushes back on me and I start rolling
What two things does an object require to have momentum?
mass and velocity
Consider an airplane at rest and a person walking through the airport.
a. Which has greater mass?
b. Which has greater velocity?
c. Which has greater momentum? Explain.
a. the airplane
b. the person
c.the airplane is not moving so the person
Explain the two different ways to calculate impulse.
ft or mv2-mv1
Is the unit used represent impulse the same as the unit for momentum? Explain.
impulse is the measure of change in momentum of a system so it has the same units as momentum
State the law of conservation of momentum in your own words.
if interacting objects in a system are not acted on by outside forces the total amount of momentum in the system cannot change
You and your little cousin are standing on inline skates. You push off of each other and both move backwards.
a. Which of you moves back at a greater speed? Use the law of conservation of momentum to explain your answer.
b. How does your impulse compare to your cousin's impulse?
a. your cousin moves faster because he has less mass. If his mass is less his velocity is greater
b. both impulses are the same because you have the same change in momentum
When you jump, you move upward with a certain amount of momentum. Earth moves downward with an equal amount of momentum. Why doesn't anyone notice the Earth's motion?
earths mass is so large that you don't notice the motion of its momentum
What is anything with energy able to do?
anything with energy is able to change or to cause change
The joule is an abbreviation for what combination of units?
Newton x meter
When work is done, _____ is transferred.
How can you increase the gravitational potential energy of an object?
increase in height
Explain why a bicycle at rest at the top of a hill has energy.
the bike has potential energy because it is capable of being active due to the force of gravity and its position at the top of the hill
Which two quantities are needed to determine an object's kinetic energy?
its mass and speed determine its kinetic energy
What happens to a car's kinetic energy if its speed doubles? What if its speed triples?
KE is proportional to the square of the velocity. if the speed doubles the KE is 4 times greater, if it triples it is 9 time greater
A ball is thrown up into the air. Explain what happens to its potential and kinetic energies as it moves up and then back down.
Up- KE decreases as it slows down and PE increases as its height increases.
Down-KE increases as it speeds up and PE decreases as height decreases
Explain what it means to say energy is conserved as a ball falls toward the ground.
as the ball falls towards the ground, its total energy is conserved. as it falls its speed increases and its height decreases. its PE is transformed to KE as it approaches the ground, but its total amount of energy stays the same.
Will we ever run out of energy on Earth? Might we run out of certain forms of energy? Explain.
total energy on earth remains constant, it will never run out. Certain forms of energy such as oil or gas may run out but thats because they've been transformed into a different type of energy. The energy is not gone, just transformed into a different type.
Distinguish between elastic and inelastic collisions.
Elastic- objects bounce off each other with no loss of KE in the system. The KE before and after the collision is the same
Inelastic-objects collide and stick together or change shape
Classify each collision as elastic or inelastic.
a. A dog catches a tennis ball in his mouth.
b. A ping-pong ball bounces off a table.
c. You jump on a trampoline.
d. A light bulb is knocked onto the floor and breaks.
Is momentum conserved during elastic collisions? Is it conserved during inelastic collisions?
momentrum is conserved during both elastic and inelastic collisions
Why does bouncing nearly always cause a greater force than simply stopping during a collision?
bouncing almost always causes a greater force because its change in momentum is greater. if it stops it velocity goes to zero. if the object bounces its velocity changes direction resulting in a larger momentum change. the force depends on the momentum change
Cars that crumple in a collision are safer than cars that bounce when they collide. Explain why this is so.
the car is designed to absorb momentum of a crush by crumpling slowly and reducing the force of impact by spreading out the change in momentum over a longer period of time
What is the secret to catching a water balloon without breaking it? Explain using physics.
to move your hands along with the water ballon to slow its impact and spread out the momentum change over a long period of time by
THIS SET IS OFTEN IN FOLDERS WITH...
Physics 1 Regular
Physics Chapter 20
Physics vocab chapter 5
YOU MIGHT ALSO LIKE...
Physics Chapter 3
Combo with "Physics Final Chapter 3.1" and 2 others
Physical Science Test I
OTHER SETS BY THIS CREATOR
Asking for and giving opinions
Spanish extra credit