Q.
A 4kg particle is moving along the x -axis under the action of the force F=−(16π2)xN. At t=2sec, the particle passes through the origin and at t=10sec its speed is 42m/s. The amplitude of the motion is:
a=−(64π2)x ⇒ω=64π2=8π ⇒T=ω2π=16sec.
There is a time difference of T/2 between t=2sec to t=10sec. Hence particle is again passing through the mean position of SHM where its speed is maximum.
i.e., Vmax=Aω=42 ⇒A=π/842=π322m.