Question

Two unequal masses of $1\text{kg}$ and $2\text{kg}$ are connected by an inextensible light string passing over a smooth pulley as shown in figure. A force $F=20\text{N}$ is applied on $1\text{kg}$ block. Find the magnitude of acceleration of either block. ($g=10{\text{m/s}}^2$)

• A. $10{\text{m/s}}^2$
• B. $\frac{10}{3}{\text{m/s}}^2$
• C. $\frac{10}{2}{\text{m/s}}^2$
• D. $\frac{10}{4}{\text{m/s}}^2$

Answer 1

The correct option is B $\frac{10}{3}{\text{m/s}}^2$

FBD of each mass
$F+g-T=a$
$T-2g=2a$
Adding both
$F-g=3a$
$20-10=3a$
$a=\frac{10}{3}{\text{m/s}}^2$