What force acts on a projectile? (neglect friction)
gravity
100
Work is defined as ____ x _____.
It is measured in ______.
Force x Distance
Joules
100
Energy can be categorized into two main types.
Name them.
Potential
Kinetic
100
In an elastic collision, the objects _____.
In an inelastic collision the objects ______ _______.
bounce
stick together
200
The earth _____ around it's axis and ______ about the sun.
rotates
revolves
200
Does the horizontal component of a projectiles velocity increase, decrease or stay the same throughout it's trajectory?
It stays the same
200
Power is defined as ____ / ____.
It is measured in what units?
Work/Time
Watts
200
What is the formula for gravitational potential energy?
PE = mgh
200
?????? is always conserved in a collision (as long as there are no outside forces)
momentum
300
The acceleration vector of an object in uniform circular motion points in which direction?
Towards the center
300
Does the vertical component of a projectiles velocity increase, decrease or stay the same throughout it's trajectory?
it increases
300
Give an example of a case where a force was applied but no work was done.
no motion - no work
300
What is the formula for kinetic energy?
KE = 1/2 m v^2
300
Kinetic energy is NOT conserved in an ______ collision.
inelastic
400
An object that is traveling at constant speed is accelerating because it's _______ is changing direction.
velocity
400
Doubling the initial velocity of a horizontally launched projectile will do what to the range?
double it
400
How much work is done by a 50 kg girl walking up a 5m high stairway?
2500 J
400
What is the kinetic energy of a 100N ball moving at 4 m/s?
80 J
400
A 100 kg car going 20 m/s rear ends a 75 kg car going 10 m/s. They stick together. How fast are they moving after the collision?
15.7 m/s
500
Convert 120 rpm to rps.
2 rps
500
A car drives off a 5m high cliff and lands 20m away. What was it's velocity as it sailed off the cliff?
20 m/s
500
How much power is required to pull a 10,000 kg roller coaster car up a 50m high track in 20 seconds?
250,000 Watts
500
Doubling the velocity of an object increases it's kinetic energy by a factor of ????.
Four
500
Two billiard balls of equal mass collide. One ball is stationary before the impact, the other is moving at 0.5 m/sec. What happens to the stationary ball?
They trade velocities so the stationary ball moves away at 0.5 m/sec.