A kettle is found to output 65J when its input energy is 100J. What is the efficiency of the kettle, and what happens to the rest of the energy?
Efficiency=useful energy /input energy x 100, so for the kettle, efficiency = 65/100 x 100 = 65% efficient. The rest of the energy is wasted as heat energy in the kettle/sound energy.
JL
Related Physics GCSE answers
All answers ▸If an object of mass 6kg was dropped from a height 35m (initially at rest), how long would it take to reach the ground under free fall?
What are Balanced Forces?
Given I climb two steps every second and I have a mass of 50kg, what is the power output of my legs in kilowatts? (3 significant figures)
A jug containing 0.250 kg of liquid is put into a refrigerator. Its temperature decreased from 20°C to 15°C. The amount of energy transferred from the liquid was 5,250 J. Calculate the specific heat capacity of the liquid.