Three equal weight `A,B` and `C` of mass `2kg` each are hanging on a string passing over a fixed frictionless pulley as shown in the figure. The tension in the string connecting weights `B` and `C` is approximately

Options

A. Zero
B. 13 N
C. 3.3 N
D. 19.6 N

Answer

B

Explanation

For `A : T - 2g = 2a `….(i)
for ` B : T_1 + 2g - T = 2a `….(ii)
for ` C : 2g -T_1 = 2a ` ….(iii)
Adding eqn.(i) and (ii ) , we get
` T_1 = 4a ` ….(iv )
from eqns (iii) and (iv)
` 2 g - 4a …. (iv)`
` or a= (g)/(3) .....(v)`
from eqns (iv ) and (v)
`T_1 = 4 xx ( 9.8 )/(3) = 13 N`