Question

Find velocity of block $B$ at the instant shown in figure. Assume the surface and pulleys to be frictionless and string to be inextensible.

• A. $25\text{m/s}$
• B. $20\text{m/s}$
• C. $22\text{m/s}$
• D. $30\text{m/s}$

Answer 1

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


Let $v$ be the velocity of block B.
Since the string is inextensible, therefore velocity along the string remains same at each section.
$v\cos 37°=20$
$v=\frac{20\times 5}{4}=25\text{m/s}$