P1 conservation and dissipation of enrgy Flashcards
1
Q
law of conservation of energy
A
energy cannot be created or destroyed
in a closed system, the total energy before and after the event is equal
2
Q
change of gravitational potential energy store
A
mass x gravitational field strength x change of height
3
Q
kinetic energy
A
1/2 x mass x speed2
4
Q
elastic potential energy
A
1/2 x spring constant x extension2
5
Q
efficiency
A
useful output / total energy input
6
Q
increasing efficiency
A
reducing wasted energy
lubrication to reduce friction between moving parts
7
Q
power
A
rate of transfer of energy
energy / time
8
Q
power wasted
A
total power input - useful power output
