Question

A stone is swinging in a horizontal circle 0.8 m in diameter at 30 rev/min.A distant horizontal light beam causes a shadow of the stone to be formed on a really vertical wall.The amplitude and period of the simple harmonic motion for the shadow of the stone are

• A. 0.4 m,4 s
• B. 0.2 m,2 s
• C. 0.4 m,2 s
• D. 0.8 m,2 s

Answer 1

Answer: (C)

0.4 m,2 s

As we see in the animation Its amplitude will be equal to its radius i.e. 0.4m and its time period will be equal to the time taken by the particle to complete one revolution. Since the particle makes 30 revolution per minute. it will take 2 minutes to complete one revolution. So the time period of the SHM is 2s.