P7.1 Work Flashcards
1
Q
Power
A
Rate at which energy is transferred
Power(W-watts) = Work(J-joules) / Change in time(s-seconds)
Power(W-watts) = Resistance(Ω-ohms) x Current² (A-amps)
Power(W-watts) = Voltage(V-volts) x Current(A-amps)
2
Q
Work
A
Using forces to transfer energy between stores
Using a force to move an object a distance
Lifting suitcases is doing work against gravity
Pulling a suitcase in a straight line is doing work against friction.
Work done (joules) = Force (N) x Displacement (m)
work done = Kinetic energy
3
Q
How many joules are in a kilojoule
A
1000
4
Q
Define power
A
The rate at which you can transfer energy
5
Q
How does lubrication increase efficiency
A
Reduces friction between objects
