Question

In the following arrangement the system is initially at rest. The $5kg$ block is now released Assuming the pulleys and string to be massless and smooth, the acceleration of block ‘C’ will be

• A. Zero
• B. $2.5m/s^2$
• C. $\frac{10}{7}m/s^2$
• D. $\frac{5}{7}m/s^2$

Answer 1

Answer: (D)

Block $B$ will not move



$5g-T=5a\dots$ (1)

$2T-8g=8\frac{a}{2}\dots$ (2)

$10g-2T=10a$ from (1)

$2g=14a$

$a=\frac{g}{7}$

$\therefore \frac{a}{2}=\frac{g}{14}=\frac{10}{14}$

$=\frac{5}{7}m/s^2$