Question

A rotating space heater used 1,400 joules of energy while heating a room. Of that total, 896 joules produced thermal energy, 181 joules produced kinetic energy, 203 joules produced light energy, and 120 joules produced sound energy. What is the space heater’s efficiency?(1 point)
Responses

36%
36%

156.25%
156.25%

64%
64%

56.25%
56.25%

Answer 1

Efficiency = (useful output ÷ total input) × 100% = (896 J ÷ 1400 J) × 100% = 64%.