Question

In forced oscillation of a particle the amplitude is maximum for a frequency ω1 of the force,

Answer 1

If a forced oscillation occurs for a body where the force applied itself is harmonic then because the body likes to have a large amplitude of oscillation at it's natural frequency then when the applied frequency is nearly equal to the natural frequency of the body then the body will undergo large amplitude oscillations.

This is also known as resonance

Answer 2

In forced oscillation of a particle the amplitude is maximum for a frequency ω1 of the force,. The maximum velocity of a particle, executing simple harmonic motion with an amplitude 7 mm, ... Two particles are executing simple harmonic motion of the same amplitude A and frequency ω along the x-axis.