Question

A block of mass $m$ is placed in contact with one end of a smooth tube of mass $M$ (see Fig.). A horizontal force $F$ acts on the tube in each case (i) and (ii). Then, immediately after applying force, the acceleration of $m$ and $M$ are:
\( M \) \( M \) (ii)

• A. Force on $m$ is $\frac{mF}{M+m}$ in (ii)
• B. $a_m=a_M=\frac{F}{M+m}$ in (ii)
• C. $a_m=a_M=\frac{F}{M+m}$ in (i)
• D. $a_m=0$ and $a_M=\frac{F}{M}$ in (i)

Answer 1

Answer: (A), (B), (D)

$a_m=0$ and $a_M=\frac{F}{M}$ in (i)

In the first case, $m$ will remain at rest.
$a_M=\frac{F}{M}$
In the second case, both will accelerate:
$a_m=a_M=\frac{F}{M+m}$
In the second case, force on $m=m{a}_m=\frac{mF}{M+m}$