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:
Acceleration of particle is a=−(64π2)x
comparing with a=−ω2x we get ⇒ω=64π2=8π ⇒T=ω2π=16s
There is a time difference of 2T between t=2s to t=10s.
Hence particle is again passing through the mean position of SHM where its speed is maximum at t=10s ⇒Vmax=Aω=42 ⇒A=π/842 =π322m.