Question

Two blocks of same mass m are connected to each other by spring of spring constant k. Initially spring is compressed by $x_0$ and blocks are connected by string. Whole system is placed on a smooth horizontal table. Now both blocks are given same horizontal velocity v perpendicular to spring and string is cut simultaneously. During subsequent motion of blocks.

Find the speed of blocks when extension in spring is maximum

• A. v
• B. $\frac{v}{2}$
• C. zero
• D. None of these

Answer 1

The correct option is A

v

Motion is SHM in vertical direction with two extreme positions at maximum compression maximum elongation respectively. Using law of conservation of energy

$2\times \frac{1}{2}m{v}^2+\frac{1}{2}k{x}_0^2=2\times \frac{1}{2}m{v}^{,2}+\frac{1}{2}k{x}_0^2$

v'=v