Question

What is the maximum compression in the spring, if the lower block is shifted to rightward with acceleration $a$.. (Given that all surfaces are smooth as shown)

• A. $\frac{ma}{2k}$
• B. $\frac{2ma}{k}$
• C. $\frac{ma}{k}$
• D. $\frac{4ma}{k}$

Answer 1

The correct option is C $\frac{ma}{k}$

If we see from lower frame of reference, a pseudo force ' ma ' acts on the block.

This ' ma ' acts backward and compress spring by $x$.

Under maximum compression the force are balanced

$kx$ = ma

$\therefore$ $x$ = $\frac{ma}{k}$ is the maximun compression.

Hence, option C is correct answer.