Question

Two masses $A$ and $B$, each of mass $M$ are fixed together by a massless spring. $A $ force acts on the mass $B$ as shown in figure. If the mass $A$ starts moving away from mass $B$ with acceleration $'a'$ , then the acceleration of mass $B$ wil be :-

• A. $\frac{ Ma - F }{ M }$
• B. $\frac{ MF }{ F + Ma }$
• C. $\frac{ F + Ma }{ M }$
• D. $\frac{ F - Ma }{ M }$

Answer 1

Answer: (D)

$a_{ cm }=\frac{ m _{1} a _{1}+ m _{2} a _{2}}{ m _{1}+ m _{2}}$
$\frac{ F }{2 M }=\frac{ Ma + Ma _{ B }}{2 M }$
$a _{ B }=\frac{ F - Ma }{ M }$