12.3 quiz
what happens when the only force acting on an object is gravity?
Free Fall
If two identical objects are moving at different velocities, the object that is moving faster will have _________________ momentum.
greater
A 740 kg car traveling 19 m/s comes to a complete stop in 2.0 s. What is the force exerted on the car during this stop?
-7030N
Your in-line skates are sitting in a box on a shelf in the closet. What is their momentum?
0 kg*m/s
A bowling ball has 9 kg m/s of momentum when it is rolled 6 m/s. What is the mass of the bowling ball?
1.5kg
A 50 kg Corvette (car) has a momentum of 500 kg m/s. How fast is the car going?
10m/s
Acelleration*Time= ?
Velocity
The momentum of a 0.225kg softball moving at 35 m/s is.....
7.9kg*m/s
All objects on earth fall at ____ m/s²
9.8
All projectiles fall with an acceleration of....
9.8m/s2
__________ ________ is any force that causes an object to move in a circle
Centripetal force
What does newton's third law state?
Every action has an equal and opposite reaction
What law says that an object at rest will remain at rest unless acted on by an outside force, and an object in motion will stay in motion unless acted on by an outside force.
Newton's first law
what type of friction is this: When an object rolls over another surface (bike tire)
Rolling
_____________ are projectiles that are put into space and fall around the earth.
Satellites
what type of friction is this: when two solid surfaces slide over each other (walking)
Sliding
There are three types of friction:
Sliding, rolling, and fluid friction.
what is the greatest velocity an object can reach?
Terminal velocity
According to Newton's third law of motion, what happens whenever one object exerts a force on a second object?
The second object exerts an equal and opposite force on the first object.
According to the law of conservation of momentum, what happens to the total momentum of a system if no net force acts on the system?
The total momentum of the system does not change
Choose the letter of each factor that affects the momentum of a moving object. a. mass b. volume c. shape d. velocity
a, d
The equal and opposite forces described by Newton's third law are called _____________ and _____________ forces.
action, reaction
When falling objects experience _____ ________________. This is what causes some object to fall more slowly than other objects.
air resistance
what is the force that one surface exerts against another when two surfaces rub together
friction
Force is...
any push or pull on an object
Choose the letters that identify each sentence that is true about action-reaction forces. a. Newton's second law describes action-reaction forces. b. Forces always exist in pairs. c. Action-reaction forces never cancel. d. All action-reaction forces produce motion.
b, c
Basically_____________ forces are equal forces acting in opposite directions.
balanced
When___________ forces act together the objects motion will not change. Like a __________see-saw.
balanced
when you have the same force on the same object, you can have___________ and____________ clocks
balanced, unbalanced
Which has a greater momentum a semi-truck at rest or a bicycle in motion?
bicycle
Centripetal means ___________ ____________.
center seeking
Satellites orbit around objects because of ______________ force
centripetal
When forces act in the same direction, they__________ to make a__________ force and when they act in opposite directions they_________ from each other to make a__________ force.
combine, stronger, subtract, weaker
What states that the total momentum of the system does not change; momentum does not increase or decrease?
conservation of momentum
what states that the total momentum of a system remains the same unless an outside force acts on it?
conservation of momentum
Choose the letter of the object that has the greatest momentum. a. a 700-gram bird flying at a velocity of 2.5 m/s b. a 1000-kilogram car traveling at 5 m/s c. a 40-kilogram shopping cart rolling along at 0.5 m/s d. a 300-kilogram roller coaster car traveling at 25 m/s
d
When a golf club hits a golf ball, the change in momentum of the club is_______ ___the change in momentum of the ball
equal to
Is the following statement true or false? Action-reaction forces do not cancel each other because the action force is always greater than the reaction force.
false; equal and opposite
what type of friction is this: When an object moves through a liquid or a gas. This includes air resistance.
fluid
_______ is a change in momentum
impulse
____________ is an objects tendency to resist change in it's motion.
inertia
When newton's third law is put into play, it is not canceled out because....
it is acting on two different objects
momentum is a way to measure___________ energy
kinetic
The amount of inertia an object has depends on its__________. More________ equals more inertia.
mass
Applying a force for a longer time increases the change in _________.
momentum
_______________ is a way to measure kinetic energy
momentum
like energy,______________ is not gained or lost, it is _____________.
momentum, transferred
Write the momentum formula, including the correct units.
momentum=mass(kg)*velocity(m/s)
what is the formula for finding momentum?
momentum=mass*velocity
The overall force after adding the forces together is called_____ ________.
net force
Friction always acts_____________ of the movement.
opposite
An object that is thrown is called a______________
projectile
However much force you push a wall with, the_______ amount of force from the wall will come back at you
same
what is any object that travels around another object in space?
satellite
Forces are not only described in how ________ something is but also in what_______________.
strong, direction
_____________ __________ is the constant velocity of a falling object when gravity equals air resistance
terminal velocity
What is weight?
the force of gravity acting on an object
The strength of friction depends on two things:
the types of surfaces and how hard they are pushed together.
Is the following sentence true or false? An object with a small mass can have a large momentum if the object is traveling at a high speed.
true
Is the following sentence true or false? In a closed system with two objects, the loss of momentum of one object equals the gain in momentum of the other object.
true
Is the following sentence true or false? Objects within a closed system can exert forces on one another, but other objects and forces cannot leave or enter the system.
true
true or false? Satellites that orbit around the earth continually fall toward the earth, but because earth is curved they end up falling around earth.
true
true or false? the faster a larger mass is going, the harder it is to stop it
true
When________________ forces act on an object the object will begin moving or its motion will change.
unbalanced
Because it is a measure of two quantities, momentum is a __________________________.
vector
how do you find weight?
w=m*g