An electric kettle. The input energy is 10 Joules. The useful output energy is heat 9
Joules. Wasted energy is sound 1 Joules.

Efficiency = 90 %

Wasted energy = 10 %

Explanation:

Since we have the input energy and useful output energy of the electric kettle, the only thing we are required to calculate here is its efficiency. This is gotten from

E = useful output energy/input energy × 100

E = 9/10 × 100 = 90 %

The percentage of wasted energy is

W = wasted energy/input energy × 100

W = 1/10 × 100

W = 10 %

the reason is because the moon has some form of gravity, and that gravity pulls the ocean tides.