mechanics-work, energy, power

Question 1

If a ball has GPE of 100 and is released what will its KE be when it hits the ground ?

Answer 1

100 only if the energy isn’t converted to anything else.

Question 2

What is the formula for gravitational potential energy ?

Answer 2

GPE = mgh

Question 3

What is the formula for efficiency ?

Answer 3

Efficiency = useful energy/total energy X 100

Question 4

What is work ?

Answer 4

Force that increase/decreases energy of something

Question 5

How would you word someone doing work on a object ?

Answer 5

The person is doing work on the box to move it.

Question 6

How would you calculate wasted energy of something if you know the GPE at the start and KE ant the end ?

Answer 6

Negate them from each other.

Question 7

What is the formula for kinetic energy ?

Answer 7

KE = 1/2 mv^2

Question 8

What are the formulae for power ?

Answer 8

P = Work done/time
P = Energy transferred/time
P = force X velocity

Question 9

What is the formula for work done ?

Answer 9

W = Fs

Question 10

What is the conservation of energy ?

Answer 10

Energy cannot be created or destroyed only transferred from one type to another.