$A$ gardener pushes a lawn roller through a distance of $20 \,m$. If he applies a force of $30 \,kg-wt$ in a direction inclined at $60^{\circ}$ to the ground, the work done by the gardener in pushing the roller is (Given: $g=9.8 \,m/s^2$) (in $\,J$)

$A$ rope is used to lower a block of mass $M$ vertically downwards by a distance $x$ with a constant downward acceleration of $g/2$. What is the work done by the rope on the block?

$A$ boy holds a uniform chain of length $2 \, m$ which is kept on a smooth table such that a length of $60 \, cm$ hangs freely from the edge of the table. The total mass of the chain is $4 \, kg$. What is the work done in pulling the entire chain on the table (in $, J$)? (Take $g = 10 \, m/s^2$)

$A$ particle of mass $m$ moves along a circular path of radius $r$ under the influence of a centripetal force $F$. What is the work done when the particle moves along a semi-circular path?

$A$ chain of mass $m$ and length $\ell$ is held on a frictionless table in such a way that its $\frac{2 \ell}{5}$ part is hanging below the edge of the table. Find the work done to pull the hanging part of the chain up onto the table.

If force and displacement of a particle in the direction of force are doubled,the work done would be: