Work, Energy And Power Flashcards
1
Q
Describe work.
A
Work done is the same as energy transferred.
Work done is the product of force and distance moved in the direction of the force.
W = Fs
Work done is a scalar quantity.
Unit = Joule
1 J = 1 Nm = 1 kg m2 s-2
Work done by a force at 90 degrees is zero.
2
Q
What is the force-energy formula?
A
Fs - Rs = 1/2 mv2 - 1/2 mu2
3
Q
Describe power.
A
Power is the rate of energy transfer.
Power = Work / Time
Unit = Watt (W)
1W = 1 J s-1 = 1 kg m2 s-3
4
Q
What are the 2 formulas for efficiency?
A
Efficiency = (work output / work input) x 100
OR
Efficiency = (Power output / Power input) x 100
