A small trailer and its load have a total weight of 500 lb. The trailer is supported by two springs, each of constant 350 lb/ft, and is pulled over a road, the surface of which can be approximated by a sine curve with an amplitude of 2 in. and a wavelength of 15 ft (that is, the distance between successive crests is 15 ft and the vertical distance from crest to trough is 4 in.). Determine

(a) The speed at which resonance will occur,

(b) The amplitude of the vibration of the trailer at a speed of 30mi/h.

Transcribed Image Text:

15 ft-