Kinetic Energy
What is the formula for calculating Kinetic Energy?
1/2mv2
What is the formula for calculating GPE?
mgh
What is the formula for calculating Elastic Potential Energy?
1/2kx2
What is the definition of Work?
The change of energy in the system due to external forces acting on our system.
What is the work-energy theorem?
Work is equal to the change in Kinetic Energy
A car with a mass of 1000 kg is traveling at a speed of 20 m/s. Calculate its Kinetic Energy. With the correct units.
200,000 J
A 2 kg object is lifted to a height of 10 meters above the ground. Calculate its Gravitational Potential Energy.
200 J
A spring with a spring constant of 100 N/m is stretched to a length of 0.2 meters. Calculate its Elastic Potential Energy.
2J
What conditions are required for negative work to be done?
A force is applied opposite the direction of motion.
Name the 2 times when no work is done
Force and displacement are perpendicular OR when a force is applied but no displacement is caused
A ball with a mass of 0.5 kg is moving with KE of 2.5J Calculate its velocity. With correct units.
3.16 m/s
What happens to the Gravitational Potential Energy of an object if its height above the ground is doubled?
A spring is stretched to a length of 0.5 meters to create 25J of EPE. Calculate its spring constant. With correct units.
200 N/m
A force of 200 N acts on an object and displaces it by 2 meters. Calculate the work done on the object.
400 J
Explain the concept of energy conservation (what can happen to the energy of a system?)
Energy cannot be created or destroyed; it is either transformed into another type of energy or transferred out of the system.
A car weighing 13,000N is moving with a velocity of 22 m/s. Calculate its kinetic energy. With correct units.
314,600 J
An object has a mass of 10 kg and a GPE of 5000J. Calculate its height above the ground. Including correct units.
50 meters
What happens to the Elastic Potential Energy of a spring if its stretch is cut by half the distance?
EPE is less by 1/4.
A force of 80 N is applied at an angle of 30o to move an object a distance of 5 meters. Calculate the work done. With correct units.
346.4 J
A roller coaster starts from rest at the top of a hill with an initial potential energy of 2000 J. If it reaches the bottom with a kinetic energy of 1500 J, calculate the total mechanical energy loss.
500J loss
How does the kinetic energy of an object change when its velocity is doubled?
KE 4 times larger
A ball weighing 5 N has a GPE of 32J. What is the height?
6.4 meters
The EPE of a spring is 19J when it is compressed by 22cm, find the spring constant. With correct units.
785.124 N/m
While the ball is rising, is the work done by gravity positive or negative? and WHY?
Negative, because force and displacement are in opposite directions (or because the ball slows down as it rises and speeds up as it falls).
A car with a mass of 1300kg is traveling with a velocity of 20m/s, then slows down over 30 meters to a new speed of 5m/s. Find the force that was acting on the car while it was breaking. Including the correct units.
- 8125 N