1
Q
what is efficiency?
A
-measure of the proportion of input energy that is transferred usefully
2
Q
machines transform an input energy into 1 or more output energies
A
3
Q
what does wasted thermal energy do
A
spreads to surroundings, warming it up
4
Q
how do we prevent wasted heat energy between 2 objects due to friction
A
lubricate parts e.g with oil
5
Q
how do we prevent wasted heat energy because of the resistance of wires when current flows
A
- use wires of lower resistance
6
Q
how do we prevent air resistance opposing motion of object
A
streamline the object to make it more aerodynamic
7
Q
how do we prevent sound created by vibrations of machinery transfers energy to surroundings
A
- tighten all loose parts
