Question

Assuming the string to be inextensible and pulley and surface to be frictionless, the speed of block B in the pulley block system as shown in figure is

• A. $5m/s$
• B. $6.5m/s$
• C. $7.5m/s$
• D. $10m/s$

Answer 1

The correct option is C $7.5m/s$

Components of the velocities of the bodies along the string should be equal as the string is inextensible.

$V_B\cos {37}^o=10\cos {53}^o$
$\Rightarrow V_B=\frac{10\times 3/5}{4/5}=\frac{15}{2}=7.5m/s$