A child sits on a swing supported by ropes of length 2.0 m.With what frequency will she need to apply the driving force to maintain swinging?
A)0.35 Hz
B)0.70 Hz
C)1.7 Hz
D)2.8 Hz
E)5.4 Hz

Question

Quizplus · Accepted Answer

The frequency of the driving force should be equal to the natural frequency of the swing. The natural frequency of a pendulum is given by f = 1/2π√(L/g), where L is the length of the pendulum and g is the acceleration due to gravity. In this case, L = 2.0 m and g = 9.8 m/s^2, so f = 1/2π√(2.0 m / 9.8 m/s^2) = 0.35 Hz.

A Child Sits on a Swing Supported by Ropes of Length