Find the earliest time at which particle has 18.85 cm/s. The amplitude is 2 cm and the frequency is 1.50Hz.?

Answer 1

With a frequency of 1.5 Hz or 9.425 rad/s, the peak velocity is exactly 2 cm * 9.425 rad/s, or 18.85 cm/s. When this peak first occurs depends on what kind of function the amplitude is (sine, cosine?). If a sine, then the velocity is a cosine and is at its peak value at t=0.