07 energy, work & power Flashcards
Definition
Work Done
The product of the force and the distance travelled in the direction of the force.
Unit: Joule, J
Factors
Work Done
- Magnitude of force
- Distance travelled in the direction of the force
Definition
Energy
The capacity to do work.
Unit: Joule, J
Forms
Energy
- Potential Energy
- Chemical
- Elastic
- Gravitational
- Electrical Energy
- Kinetic Energy
- Light Energy
- Nuclear Energy
- Sound Energy
- Thermal Energy
Definition
Kinetic Energy
Energy a body possesses due to its motion.
Formula
Kinetic Energy
EK = 1/2 mv2
m = mass
v = velocity
Definition
Gravitational Potential Energy
Energy which an object possesses because of its position relative to the ground.
Formula
Gravitational Potential Energy
EGPE = mgh
m = mass in kg
g = gravitational field strength
h = height in m
Definition
Principal Of Conservation Of Energy
Energy cannot be created or destroyed but only converted from one form to another. The total energy in an isolated system remains constant.
Definition
Power
Rate of doing work.
Formula
Power
Work done/ Time taken
Formula
Efficiency
(Useful energy output/ Input energy) x 100%
