Question

The speed of block $A$ in the system shown in the figure is (String is massless and inextensible)

• A. $4\text{m/s}$
• B. $6\text{m/s}$
• C. $8\text{m/s}$
• D. $10\text{m/s}$

Answer 1

The correct option is D $10\text{m/s}$

The given arrangement can be depicted as shown

Since, the string is inextensible, the velocities of both the object i.e. Ring and block $A$ should be along the string otherwise, string will break.

So, the component of velocity of ring along string = speed of A
$\Rightarrow \frac{50}{3}\cos {53}^{\circ }=V_A\Rightarrow V_A=10\text{m/s}$

$\therefore \cos {53}^{\circ }=\frac{3}{5}$