Question

Two blocks of masses $2.9\, kg$ and $1.9 \,kg$ are suspended from a rigid support $S$ by two inextensible wires each of length $1 \,m$ (figure). The upper wire has negligible mass and the lower wire has a uniform mass of $0.2\, kg/m$. The whole system of blocks, wires and support have an upward accelration of $0.2\,m/s^{2}$ . The tension at the mid-point of the upper wire is

• A. 20 N
• B. 30 N
• C. 40 N
• D. 50 N

Answer 1

Answer: (D)

50 N

Answer 2

The tension at $A =\left(m_{1}+m_{2}\right)(g+a)$ $=(2.9+1.9)(9.8+2)=50\, N$