Level 1
The ability to do work
What is energy?
Potential energy is maximum at small heights and kinetic energy is maximum as high heights
False
A 60 kg skydiver jumps from a plane at an altitude of 500 m. What is her PE before she jumps?
PE = 294,000 J
If a car of 600 kg starts from rest and accelerates to 10 m/s. How much work is done by the engine?
30,000 J
Work done over time
What is power
1/2*m*V2 is the formula for what?
Kinetic Energy
A roller coaster car loaded with people has a mass of 10,000 kg. When it reaches the bottom of a hill, its velocity is 5 m/s. What is it's KE?
KE = 125,000 J
A 70 kg runner starts to get tired and decelerates from 5 m/s to 1 m/s. What work is done to slow them down?
- 840 J
Amount of force applied for a certain distance
What is work?
If John and Peter have the same job and complete the same labour but Peter does it twice as quickly as John, what is different between them?
A) Energy
B) Work
C) Power
D) nothing, they're the same
C) Power!
A car in a race is acted on by a force of 30 N. Find the work done on the car as it moves along a 20 m length of straight track
Work = 600 J
A 6 kg watermelon is dropped off the top a 10 m tall building. What is its velocity when it hits the ground?
- 14 m/s
The change in kinetic energy
What is work?
If you move a 4 N box 2 meters across the floor of an elevator that is moving up 30 m, how much work did you do vertically?
0 J
A skateboarder of mass 60 kg decelerates from 6 m/s to 2 m/s. How much work does the friction do to slow her down?
-960 J
A 15 kg child rolls down a frictionless hill 4 m tall. What is its velocity when it hits the ground?
- 8.85 m/s