A uniform chain of length \(L\) and mass \(M\) is lying on a smooth table and one-third of its length is hanging vertically down over the edge of the table. If \(g\) is the acceleration due to gravity, the work required to pull the hanging part on the table is:
1. \(MgL\)

2. \(\dfrac{MgL}{3}\)

3. \(\dfrac{MgL}{9}\)

4. \(\dfrac{MgL}{18}\)

1. \(u^{2} \sin^{2}\alpha\)

2. \(\dfrac{m u^{2} \cos^{2} \alpha}{2}\)

3. \(\dfrac{m u^{2}\sin^{2} \alpha}{2}\)

4. \(- \dfrac{m u^{2}\sin^{2} \alpha}{2}\)

What is the work done by gravity on block \(A\) in \(2\) seconds after the blocks are released? (Pulley is light)

1. \( 240 ~\text J\)
2. \( 200 ~\text J\)
3. \(120 ~\text J\)
4. \( 24 ~\text J\)