A kettle has an input of 1000J electrical energy. 100J of energy is transferred as sound and 50J of energy is transferred as light energy. 100J is transferred to the surroundings as thermal energy. The remaining energy is transferred to the water as thermal energy. What is the efficiency of the kettle?

The efficiency of the kettle is 75%

Step-by-step explanation:

Given;

total input energy of the kettle, Qi = 1000 J

energy transferred as sound = 100 J

energy transferred as light = 50 J

energy transferred to surrounding =  100 J

Total lost energy = 100 J + 50 J + 100 J

Total lost energy = 250 J

Total output energy = 1000 J - 250 J  = 750 J

Efficiency of the kettle is given by;

Therefore, the efficiency of the kettle is 75%

where r the answers

step-by-step explanation: