Consider the system shown in fig. the system os released from rest, find the tension in the cord connected between 1kg and 2 kg blocks.

Explanation

By Newton's law, we have
`1g-T_(1)=1a` …(i)
`T_(1)+2g)-T_(2)=2a` …(ii)
and `T_(2)-2g=2a` …(iii)
Solving eqs (i), (ii) and (iii) we get `a=2 ms^(-2),T_(1)=8N`,
and `T_(2)=24 N`
By shortcut method:
`a=([(2+1)-2]g)/((1+2+2))=2ms^(-2)`
`T_(1)=m(g-a)=1(10-2)=8N`.