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 %

force required to detach it is given by

charges are taken to be fundamental charge

now we have

so above is the minimum distance at which it will detach

the answer is false. this is because for ice to melt, it requires latent heat of melting. latent heat means heat energy required to change phase without any increase in temperatures. therefore, the ice will take energy from the environment to melt hence atmospheric temperatures will reduce.