Q. In the figure-$2.136$ at the free end of the light string, a force $F$ is applied to keep the suspended mass of $18\, kg$ at rest. Assuming pulley is light then the force exerted by the ceiling on the system is : (Take $g=10\, m / s ^{2}$ )

Laws of Motion Report Error

A

$200\, N$

B

$120\, N$

C

$180\, N$

D

$240\, N$

Solution:

$3 F =180 $
$F =60 N $
Force exerted by the ceiling on the system,
$F_{s}=4 F$
$=4 \times 60$
$=240\, N$

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