# The Physics of Work, Energy and Power

11 questions covering topic 2.9 Work, Energy and Power. Requires knowledge of the equations related to those three terms and their definitions as well as some of the conservation laws of mechanics.

The equation which represents the work done on an entity is...? (given that values s is the extension vector and F is a force at an acute angle)
Work Done = Fcosθ x Δs
1 of 10
What is the definition of Energy and it's effect?
Energy allows body A to do work on body B, transferring energy from body A to body B
2 of 10
For a spring, the area under a graph of Force (y axis) against Extension (x axis) (and therefore work done) can be calculated by...? (where s is the vector of extension parallel to force F)
Area = ½FΔs
3 of 10
For a spring, the work done in extending the spring can be expressed by the equation...?
Area = ½F(Δs^2)
4 of 10
The equation defining the kinetic energy (K.E.) of an entity is...? (where m is the mass and v is the velocity of the entity)
K.E. = ½m(v^2)
5 of 10
The law of Conservation of Energy states...?
Energy can neither be created nor destroyed, it can only be changed into another form
6 of 10
An elastic collision is one in which...?
Both kinetic energy and momentum are conserved
7 of 10
In general, in an inelastic collision...?
Momentum is conserved but kinetic energy is not
8 of 10
The SI and traditional units of power are...?
Power = Joules/second (Watts)
9 of 10
Efficiency as defined as...?
The useful work done per unit of the total energy put in to a system (work done / total energy)
10 of 10

## Other cards in this set

### Card 2

#### Front

What is the definition of Energy and it's effect?

#### Back

Energy allows body A to do work on body B, transferring energy from body A to body B

### Card 3

#### Front

For a spring, the area under a graph of Force (y axis) against Extension (x axis) (and therefore work done) can be calculated by...? (where s is the vector of extension parallel to force F)

### Card 4

#### Front

For a spring, the work done in extending the spring can be expressed by the equation...?

### Card 5

#### Front

The equation defining the kinetic energy (K.E.) of an entity is...? (where m is the mass and v is the velocity of the entity)