Which is the equation for a machine's efficiency?
A. Efficiency = input energy + output energy
B. Efficiency = output energy/ input energy • 100
C. Efficiency = input energy - output energy
D. Efficiency = input energy/ output energy • 100
A. Efficiency = input energy + output energy
B. Efficiency = output energy/ input energy • 100
C. Efficiency = input energy - output energy
D. Efficiency = input energy/ output energy • 100