question_answer

In an engine the piston undergoes vertical simple harmonic motion with amplitude 7cm. A washer rests on top of the piston and moves with it. The motor speed is slowly increased. The frequency of the piston at which the washer longer stays in contact with the piston, is closed to:                                                                [JEE ONLINE 10-04-2016]

A)  0.7 Hz

B)       1.2 Hz

C)  1.9 Hz

D)       0.1 Hz

Correct Answer: C

Solution :

[c]