Question

A kettle transfers 1,500 J of energy, 1,200 J to a thermal energy store in the water and 300 J to the air as sound. How efficient is the kettle?

Answer 1

80%

Step-by-step explanation:

Given data

The energy use is the 1200J transfered to the water

Total energy=1500J

Efficiency = Energy used/total enery

Efficiency= 1200/1500*100

Efficiency=0.8*100

Efficiency=80%

Hence the efficiency of the kettle is 80%