Question

Two bodies of masses $2\text{kg}$ and $4\text{kg}$ are tied to the ends of a massless string. The string passes over a pulley which is frictionless as shown in figure. If the system is released from rest, then tension in the string connecting the bodies will be $(g=10{\text{m/s}}^2)$

• A. $80\text{N}$
• B. $\frac{80}{3}\text{N}$
• C. $20\text{N}$
• D. $\frac{20}{3}\text{N}$

Answer 1

The correct option is B $\frac{80}{3}\text{N}$


for $4\text{kg}$ block
$4g-T=4a\dots \left(i\right)$
for $2\text{kg}$ block
$T-2g=2a\dots \left(ii\right)$
On solving (i) and (ii)
$T=\frac{2\times 2\times 4\times 10}{6}\Rightarrow T=\frac{80}{3}\text{N}$