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` , as shown in figure.The upper wire has negligible mass and the lower wires and support have an uniformly distributed mass of `0.2 kg` .The whole system of blocks, wire and support have an upwards acceleration of `0.2 m//s^(2)`. Acceleration due to gravity is `9.8 m//s^(2)`.
(a) Find the tension at the mid point of the lower wire.
(b)Find the tension at the mid point of the upper wire.

Explanation

As the system is accelerated upwards , therefore, tension at any point is given by
` T = m (g+a) `
for the point A , ` m = 2.9 + (0.2)/(2) = 3.0 `
` :. T_(A) = m (g+a) = 3 (9.8+ 0.2 ) = 30 N `
For the point B
` m = 2.9 + 0.2 + 0.9 + 0 = 5 kg `
`:. T_(B) = m (g+ a ) = 5 (9.8+ 0.2) = 50 N` .