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 ▸How do current and voltage vary in series and parallel circuits, respectively?
What is the difference between acceleration, speed and velocity?
A roller coaster car starts stationary at the top of a downwards slope. At the bottom of the slope, it has a speed of 30m/s. Use the conservation of energy to find the vertical height of the slope. (Use g=10 m/s^2)
How does conduction work in metals?