In the figure, pulleys are smooth and strings are massless, m_(1)=1 kg and m_(2)=(1)/(3)kg. To keep m_(3) at rest, mass m_(3) should be

In the figure, pulleys are smooth and strings are massless, m_(1)=1 kg

1.	In the figure, pulleys are smooth and strings are massless, m_(1)=1 kg and m_(2)=(1)/(3)kg. To keep m_(3) at rest, mass m_(3) should be
Answer» 1 kg `(2)/(3)kg` `(1)/(4) kg` `2 kg` Solution :(a) `m_(3)` is at rest, Therefore 2T`=m_(3)g`….(i) Further if `m_(3)` is at rest, then pully P is also at rest. Writing equations of motion. `m_(1)g-T=m_(1)a` ….(II) `T-m_(2)g=m_(2)a` ...(iii) Solving Eq. (ii) and (iii) we GET, `m_(3)=1 kg `