Question

A particle in simple harmonic motion is described by the displacement function x(t)=Acos⁡(ωt+θ). If the initial (t=0) position of the particle is 1cm and its initial velocity isπcm/s, what is its amplitude? The angular frequency is the particle is πrad/s.

(a) 1 cm

(b) √2 cm

(c) 2 cm

(d) 2.5 cm

I got this question during an internship interview.

This intriguing question comes from Wave Motion in section Waves of Engineering Physics I

Answer 1

Right option is (b) √2 cm

Explanation: v=ω√(A^2-x^2)

π=π√(A^2-1)

A^2-1=1 or A^2=2

A=√2cm.