Forces and Motion
An object that is sitting still has ______ forces acting on it.
balanced
unbalanced
balanced
The _____ energy of a roller coaster is the energy of its motion.
potential
kinetic
kinetic
_____is transformed or transferred; it cannot be made or destroyed.
Energy
Momentum
Energy
Which is kinetic energy?
a. the energy of a moving object
b. energy that is decreasing
c. energy that is stored in the position, or structure, of an object
a. the energy of a moving object
The law of conservation of energy states that energy cannot be _____ or _____.
a. gained; released
b. used; wasted
c. created; destroyed
d. heated; frozen
c. created; destroyed
Objects in motion tend to stay in motion because of the property of ________.
inertia
gravity
inertia
Stretching a coil or spring increases its __.
potential energy
kinetic energy
direction
speed
potential energy
Which is not an example of a collision causing energy transfer and change in motion?
a. a bat strikes a baseball
b. a catcher catches a baseball
c. a baseball hits the ground
d. a baseball flies through the air
d. a baseball flies through the air
Which is potential energy?
a. the energy of a moving object
b. energy that is decreasing
c. energy that is stored
c. energy that is stored
As the amount of force on an object increases, the acceleration of the object _______ .
increases
decreases
increases
If you drop a rock in a lake, the rock will slow down because the water exerts ____.
a. gravity
b. less resistance
c. drag forces
d. velocity
c. drag forces
Suppose you are riding a bike. As you increase speed, your ____________
a. energy of motion increases
b. energy of motion decreases
c. stored energy increases
d. energy is used up
a. energy of motion increases
During a collision, some energy can be transferred into ______ or sound.
force
heat
electricity
conservation
heat
_______ is measured using the speed and direction of an object.
a. velocity
b. inertia
c. force
a. velocity
If two puppies pull on a plastic ring with equal force, the ring does not move. This is an example of _____.
balanced forces
unbalanced forces
acceleration
friction
balanced forces
How can you determine the speed of a moving train?
a. Divide the distance traveled by the time spent moving.
b. Divide the time spent moving by the direction traveled.
c. Multiply the distance traveled by the time spent moving.
d. Multiply the kinetic energy by the distance traveled.
a. Divide the distance traveled by the time spent moving.
How can the speed of a dropped ball be increased?
a. Roll it down a hill instead to increase the amount of friction.
b. Drop a larger ball to increase the amount of friction.
c. Decrease the height from which it is dropped to give it more potential energy.
d. Increase the height from which it is dropped to give it more potential energy
d. Increase the height from which it is dropped to give it more potential energy
Friction during a collision causes some kinetic energy to be changed into _____.
heat
electricity
potential energy
chemical energy
heat
What is force?
a. a push or a pull on something that can make it move, stop moving, or change direction
b. how fast an object moves
c. a change in velocity over time
a. a push or a pull on something that can make it move, stop moving, or change direction
The more friction between colliding objects, the ______ heat produced during a collision.
more
less
more
What causes heat when rubbing your hands together?
friction
If the amount of kinetic energy an object has is _____ , then the object will move faster.
increased
decreased
increased
The collision of two marbles can cause the _____ of both marbles to change.
energy
motion
motion
What is friction?
a. the tendency of an in object motion to stay in motion
b. any push or pull
c. a force between surfaces that slow objects or stops them from moving
c. a force between surfaces that slow objects or stops them from moving
Which has the most kinetic energy?
a. a wagon moving at 2 meters/second
b. a wagon moving at 4 meters/second
c. a wagon moving at 6 meters/second
d. a wagon moving at 8 meters/second
d. a wagon moving at 8 meters/second