Chapter 2- Work & Power Flashcards
1
Q
Work
A
Work is done whenever a force moves something.
Everyday examples include walking upstairs, lifting heavy objects, pulling a sledge and pushing a shopping trolley. Whenever work is done, energy is transferred from one place to another.
2
Q
Calculating work done
A
Work done= force x distance W= F x d Where: W is measured in joules, J F is measured in newtons, N d is measured in meters, m
3
Q
Gravitational potential energy
A
The amount of GPE an objecton earth has depends on its:
- mass
- height above the ground
4
Q
Calculating change in GPE
A
GPE= mgh GPE= m x g x h M= mass in kg G= gravitational field strength in N/kg H= change of height in m
5
Q
Kinetic energy
A
All moving object have KE. The KE an object has depends on its
- mass
- speed
6
Q
Calculating KE
A
KE= 1/2 mv2 Or KE= 1/2 x m x v2 Where: KE is kinetic energy in joules, j M is mass in kilograms, kg V= speed in meters per second, m/s
7
Q
Work, GPE and KE
A
Work done and energy are both measured in joules because work done is equal to energy transferred.
8
Q
Calculating power
A
Power= current x voltage
