A particle of mass 2 kg executes SHM in the x–y plane between A and B under force F⃗ = Fₓî + Fᵧĵ. Minimum time from A to B is 1 s. At t=0, x=2 and y=2. Find Fₓ as a function of time.

Question

G1 Physics · Accepted Answer

The minimum time from one extreme A to the opposite extreme B is T/2=1 s, so T=2 s and ω=π rad s⁻¹. At t=0, x=2 at an extreme, hence x=2 cosπt. Then aₓ=-ω²x=-2π² cosπt. With mass 2 kg, Fₓ=maₓ=-4π² cosπt N. Correct answer: A.