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
Correct Answer:
D
Solution :
The tension at A \[=({{m}_{1}}+{{m}_{2}})\,(g+a)\] \[=(2.9+1.9)(9.8+2)\] = 50 N