Question

A 500 gram mass is attached to horizontal spring. The spring is initially stretched by 20 cm and mass is released from rest there. After 0.2 s, speed of mass is zero. Find speed of block when it crosses mean position.

• A. $\pi m/s$
• B. $\frac{\pi }{4}m/s$
• C. $\frac{\pi }{2}m/s$
• D. $\frac{\pi }{3}m/s$

Answer 1

The correct option is A $\pi m/s$

$V_{max}=A.\omega$

At mean speed is maximum and equal to $A\omega$

$V=A.\omega$

$=0.2\times \frac{2\pi }{T}$

$=\frac{0.4\pi }{T}$ $\left\{\begin{array}{c}\frac{T}{2}=0.2\\ T=0.4\end{array}\right\}$

$=\frac{0.4\pi }{0.4}=\pi m/s$