P1.7 Energy and efficiency Flashcards
1
Q
equation for efficiency
A
useful energy in/ useful energy out
2
Q
what does it mean if a machine is 30% efficient
A
30% of its energy is usefully transferred and 70% is dissipated
3
Q
what’s the unit that represents one transferred per second
A
watt
4
Q
no energy transfer can be more than what % of efficiency
A
100
5
Q
in what ways to machines waste energy
A
friction on moving parts, noise, air resistance
6
Q
how can you increase efficiency on machines
A
lubricant and streamlining
