Question

At the local playground a child on a swing has a speed of 2.14 m/s when the swing is at its lowest point.
(a) To what maximum vertical height does the child rise, assuming he sits still and "coasts"? Ignore air resistance.


(b) To what maximum vertical height does the child rise if the speed is reduced to 1/5 the initial speed?

Answer 1

(a) The maximum vertical height the child rises is equal to the kinetic energy of the swing at its lowest point, divided by the gravitational force. This is equal to (2.14 m/s)^2 / (2 * 9.8 m/s^2) = 0.44 m.

(b) The maximum vertical height the child rises is equal to the kinetic energy of the swing at its lowest point, divided by the gravitational force. This is equal to (1/5 * 2.14 m/s)^2 / (2 * 9.8 m/s^2) = 0.044 m.