Question

In the figure shown, find the force exerted by the pulley at the support. Make necessary assumptions and take $g=10m/s^2$

.

• A. $16N$
• B. $32N$
• C. $64N$
• D. $72N$

Answer 1

The correct option is C $64N$


Acceleration of the system
$a=\frac{\text{Net force}}{\text{Total mass}}$
$=\frac{8g-2g}{8+2}=\frac{6\times 10}{10}=6m/s^2$

For the $2kg$ block:

$T-2g=2a$
$\Rightarrow T=2(g+a)=2\times 16=32N$

For the pulley:

$F=2T=64N$
$\therefore$ the force exerted by the pulley on the support is $64N$.