Question

A 36 kg child sits in the bed of a 3300 kg pickup truck over the rear right wheel and causes the spring to compress by 1.0 cm. The child then hops into the cab of the truck with his 90 kg dad and they go for a drive and hit a bump on the road and start to oscillate. Find the frequency of the oscillations.

Answer 1

Using the formula, F = kx,
Where k is the spring constant and x is the compression,
k = F/x
= mg/x
Where m is the mass of the child
k = (36 x 9.8) / 0.01
= 35280 N/m

Angular frequency of oscillation, = SQRT[k/M]
Where M = 36 + 90 + 3300 = 3426
= SQRT[35280/3426]
= 3.21 rad/s

Frequency, f = /2
= 0.51 Hz