Question

A board of mass $m=11kg$ is placed on the floor and a man of mass $m=70kg$ is standing on the board as shown (Case$-I$). The coefficient of friction between the board and the floor is $m=0.25$. If in Case$-II$ all surfaces are frictionless and the man hang on the rope without touching the board. The ratio of $a/A$ is:

• A. $2$
• B. $\frac{1}{2}$
• C. $1$
• D. None of these

Answer 1

The correct option is A $2$


Constraint relation: Considering movable pulley
$A=\frac{a+0}{2}$
$\frac{a}{A}=2$