2 - Work, Energy and Power

Question 1

What units does Power use?

Answer 1

Watts (W)

Question 2

What is the formula for work done?

Answer 2

Work done (J) = F in direction of motion (N) x distance moved in direction of force (m)

Question 3

What is the formula for wokr done against gravity?

Answer 3

mgh

Question 4

What is the formula for kinetic energy?

Answer 4

KE (J) = 0.5 x m (kg) x v^2 (ms-1)

Question 5

What is the formula for gravitational potential energy?

Answer 5

GE (J) = mgh

Question 6

What is work done?

Answer 6

A change in kinetic energy

Question 7

What is the work energy principle?

Answer 7

The change in total energy of a particle is equal to the work done on the particle

Question 8

What is the principle of conservation of mechanical energy?

Answer 8

When no external forces other than gravity do work on a particle during its motion, the sum of the particle’s kinetic energy and potential energy remains constant

Question 9

What is the principle of conservation of mechanical energy?

Answer 9

When no external forces other than gravity do work on a particle during its motion, the sum of the particle’s kinetic energy and potential energy remains constant

Question 10

What is power?

Answer 10

Rate of doing work

Question 11

Give the equation for power.

Answer 11

P (W) = driving force (N) x v (ms-1)