Question

Three equal wts. of mass 2kg each are hanging on a string passing over a frictionless pulley . What is the tension in the string connecting the wt.B and C

Answer 1

Let the required tension be T and the tension in the string connecting A and B be T 1 

equations are: 

for C = 2 g - T = 2 a            (i) 

for B = 2 g + T - T 1 = 2 a           (ii) 

and T 1 - 2 g = 2 a        (iii) 

adding (i), (ii), (iii) 

2 g = 6 a or a = g/3 

substituting in (i) = T = 2(g -a) = 2(g - g/3) = 4 g/3 

= 4(9.81)/3 = 13.08 N