Question

As shown in the figure, a horizontal force of $70N$ is applied on system of block of masses $4kg$, $2kg$ and $1kg$ placed on a frictionless horizontal surface. If the tension in one string is $T_1=60N$, find the tension $T_2$ in the second string.

Answer 1

According to the newton's law of motion , $F=(m_1+m_2+m_3)a$

$\Rightarrow a=\frac{F}{m_1+m_2+m_3}=\frac{70}{7}=10m/s^2$

$T_2=m_{3}a=4\times 10=40N$