Question

In the given constraint, if the pulley is frictionless and the string is inextensible, then velocity of block $B$ $\left(V_B\right)$ is

• A. $10\text{m/s}$
• B. $15\text{m/s}$
• C. $20\text{m/s}$
• D. $25\text{m/s}$

Answer 1

The correct option is D $25\text{m/s}$


If we take upward direction as +ve then
Velocity of pulley, $V_p=\frac{V_A+V_B}{2}$
$10=\frac{-5+V_B}{2}$
$V_B=25\text{m/s}$ (in upward direction)