Question

An object of mass 0.2kg executes simple harmonic motion along the x-axis with a frequency of (25/π)Hz. At the position x = 0.04, the object has kinetic energy of 0.5J and potential energy 0.4J. The amplitude of oscillation is?

(a) 6cm

(b) 4cm

(c) 8cm

(d) 2cm

I have been asked this question in examination.

The query is from Oscillatory Motion topic in portion Oscillations of Engineering Physics I

Answer 1

Right answer is (a) 6cm

The best explanation: Total energy,

E=2π^2 mv^2 A^2

0.5+0.4=2π^2×0.2×(25/π)^2 A^2

A^2=0.9/(0.4×25^2)

A=3/(2×25)=3/50 m=6cm.