Question

Three blocks of masses $2\, kg , 3 \,kg$ and $5 \,kg$ are connected to each other with light string and are then placed on a frictionless surface as shown in the figure. The system is pulled by a force $F=10 \,N$, then tension $T_{1}=$

• A. 1 N
• B. 5 N
• C. 8 N
• D. 10 N

Answer 1

Answer: (C)

8 N

Answer 2

Total mass of the system, $M=m_{1}+m_{2}+m_{3}$ $=2+3+5$ $=10\, kg$ Force $F=10\, N$ Hence, acceleration, $a=\frac{F}{M}=1 \,ms ^{-2}$ Now, tension $T_{1}$ can be calculated as, $T_{1}=\left(m_{2}+m_{3}\right) a=8 \times 1=8\, N$