Suppose wave pulses in an aquarium are produced by a mechanical motor that moves a bob up and down at the surface. The setup uses a 10-W motor and has a period of 1.9 s between bobs. How much kinetic energy is in each pulse.

kinetic energy in each pulse = 9.5J

Explanation:

The concept used here is that of work, energy and power.

Power P = Work / Time

Work = energy in this case

E = Power x time = Pt

but Power = 10W and t = 1.9s

Energy E = 10W x 1.9s = 19J

Conventionally, overall energy = kinetic + potential

Hence kinetic energy in each pulse = half of the total energy = 0.5 x 19

energy = 9.5J