5 kg collar can slide on a frictionless horizontal rod and is attached to a spring with constant k. It is acted upon by

[answerhappygod]

5 kg collar can slide on a frictionless horizontal rod and is
attached to a spring with constant k. It is acted upon by a
periodic force of magnitude P = Pm sin ωft, where Pm = 15 N and ωf
= 10 rad/s. Determine the value of the spring constant k knowing
that the motion of the collar has an amplitude of 150 mm. and is
(a) in phase with the applied force, (b) out of phase with the
applied force