Energy and efficiency Flashcards
1
Q
What is the equation for work done with force and distance?
A
W = Fs
2
Q
What is the equation for Pout?
A
work done by the machine / time taken
= Fvt /t = Fv
output power = Fv
3
Q
What is useful energy?
A
energy transferred for a purpose
4
Q
What is the equation for the efficiency of a machine?
A
useful energy transferred by the machine / energy supplied to the machine
work done by the machine / energy supplied to the machine
output / input
5
Q
Why can’t we insulate machines?
A
prevent overheating
6
Q
How does windpower work
A
large bladesd move
1/2 mv2
kinetic energy per unit of air = 1/2 (density) v2
