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 the gravitational force on block \(A\) during the first \(2\) s after the blocks are released? (assume the pulley is light)

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