Topic 1a - energy transfers (7. efficiency) Flashcards
1
Q
what is efficiency?
A
the less energy that is wasted the more efficient an object is
2
Q
formula for efficiency…
A
efficiency = useful output energy transfer / total input energy transfer
x 100 to get the %
3
Q
statement about wasted energy
A
no device is 100% efficient and the wasted energy is usually transferred to useless thermal energy stores.
4
Q
name a device that is almost 100% efficient
A
electric heaters
5
Q
how to improve efficiency
A
by insulating objects, lubricating, making them more streamlined.
