Work, Power, and Energy
The energy compressed spring stores energy because of its position
What is Elastic Potential Energy?
An object moves at constant velocity. What can be concluded about the net force acting on it?
No net force
What information does the slope of a distance‑time graph represent?
Speed or velocity
Two carts collide and stick together. What type of collision is this?
Perfectly Inelastic collision
Name 2 vector and 2 scalar quantities
Vector: velocity, displacement, acceleration, momentum, weight
Scalar: speed, distance, time, mass, volume
Two students lift the same box to the same height. One lifts it much faster. Which student uses more power, and why?
The one lifting faster uses more power because P=W/t so a smaller time means bigger power.
A book rests on a table that is on an incline. Name 3 forces acing on the book.
Friction, Gravity, Normal
A car travels at a constant speed of 15 m/s for 20 seconds. Calculate the distance traveled.
300 meters
Which quantity depends only on mass? Which quantity depends on both mass and velocity?
Mass: Inertia
Mass and velocity: Momentum
What is the direction of centripetal force on an object moving in a circular path?
Inward, toward the center of the circular path
A machine uses 67000 joules of work in 1 minute and 7 seconds. Calculate the power output of the machine.
1000 Watts
Why does a seatbelt reduce injury during a car crash?
It increases the time over which momentum changes, reducing the force
How does the velocity/speed of an object change if the acceleration is directed opposite the motion?
Decreases (The object slows down)
A 4.4‑kg cart moves at 5.7 m/s. Calculate its momentum.
25 kg*m/s
Calculate the gravitational force on a 10‑kg object near Earth’s surface.
98 N
Explain why no work is done when an object is pushed horizontally but does not move.
There is no displacement in the direction of the applied force
A 38‑kilogram object accelerates at 8 m/s². Calculate the net force acting on the object.
304 newtons
A ball is kicked horizontally from the top of a cliff that is 20.0 meters above the ground.
Calculate the total time the ball is in the air before it hits the ground.
2 seconds
A small car and a large truck crash into one another and exert equal forces. Which experiences the greater acceleration, and why?
Smaller car, less mass
A 1.20 × 10³‑kilogram car travels at a constant speed of 18.0 meters per second around a horizontal, circular track with a radius of 40.0 meters.
Calculate the magnitude of the centripetal acceleration of the car.
8.1 m/s2
A student lifts a 6.5 kg backpack 1.6 meters straight up with a constant velocity of 1.8 m/s. What is the work and power done by the student on the backpack?
Work: 102 J
Power: 184 W
State Newton’s third law as it applies when a runner pushes backward against the ground.
The ground pushes forward on the runner with an equal and opposite force.
A ball is thrown from ground level at an angle of 40° above the horizontal with an initial speed of 20.0 meters per second. Air resistance is negligible.
Calculate the maximum height reached by the ball.
8.5 meters
Two carts on a frictionless, horizontal track move toward each other. Cart A, with a mass of 2.0 kilograms, is moving to the right at 4.0 meters per second. Cart B, with a mass of 3.0 kilograms, is moving to the left at 2.0 meters per second. The two carts collide and stick together.
Calculate the magnitude and direction of the final velocity of the combined carts after the collision.
0.4 m/s to the right
If the distance between two objects is cut in half, how does the gravitational force between them change?
Increases by 4 times