Figure shows three blocks of mass m each hanging on a string passing over a pulley. Calculate the tension in the string connecting A to B and B to C?

Explanation

Net pulling force
`=2 mg-mg=mg`
Total mass `= m+m+m=3m`
Acceleration, `a=(mg)/(3m)=(g)/(3)`
Considering block A,
`T_(1)-mg=ma`
or `T_(1)=mg+ma`
or `T_(1)=mg+m((g)/(3))`
or `T_(1)=(4)/(3)mg`,
Considering block C,
`mg-T_(2)=ma` or `T_(2)=mg-ma`
or `T_(2)=mg-(mg)/(3)=(2)/(3)mg`.