Fig show two bodies A and B of masses 2.5 kg and 2.8 kg respectively from a rigid support by two inextensible wires each of length 1.8 m . The upper wire is of negligible mass and lower wire is of mass 1.5 kg // m . If the entire system moves upwards with an acceleration of 2 m//s^(2), find tension (i) at middle point p of upper wire (ii) at middle point Q of lower wire . Take g =10 m//s^(2) .

Fig show two bodies A and B of masses 2.5 kg and 2.8 kg respectively f

1.	Fig show two bodies A and B of masses 2.5 kg and 2.8 kg respectively from a rigid support by two inextensible wires each of length 1.8 m . The upper wire is of negligible mass and lower wire is of mass 1.5 kg // m . If the entire system moves upwards with an acceleration of 2 m//s^(2), find tension (i) at middle point p of upper wire (ii) at middle point Q of lower wire . Take g =10 m//s^(2) .
Answer» <P> Solution :As the SYSTEM moves upwards with an acceleration ` a = 2 m// s^(2) ` `:.` tension in the wire `T= R = m (g+a)` (i) For point P at point of upper wire `m= m_(A) + m_(B)` + mass of lower wire `= 2.5 + 2.8 + 1.8 xx 1.5 = 8.0 kg` `:. T = 8 (10+2) = 96 N` (ii) For point Q mid point of lower wire `m = m^(B)` + mass of half LENGTH of lower wire `= 2.8 + (1.8)/(2)xx 1.5 = 4.15 kg ` `:. T = m (g+a) = 4.15 (10+2) = 49.8 N` .