$A$ force $F = (5\hat i + 3\hat j) \, N$ is applied to a particle,which displaces it from its origin to the point $r = (2\hat i - 1\hat j) \, m$. The work done on the particle is:

When is the work done by a force positive and when is it negative?

$A$ block of mass $2 \,kg$ is pulled at a constant speed with a taut rope along a frictionless plane that is inclined at $30^{\circ}$. Then the work done by the tension in the rope in pulling it a distance $4 \,m$ along the inclined plane in joule is (acceleration due to gravity $= 10 \,ms^{-2}$)

$A$ force of $(3\,\hat i + 4\,\hat j) \, N$ acts on a body and displaces it by $(3\,\hat i + 4\,\hat j) \, m$. The work done by the force is .............. $J$.

$A$ weightlifter lifts a weight off the ground and holds it up.

$A$ force $\overrightarrow F = (5\hat i + 4\hat j) \ N$ acts on a body and produces a displacement $\overrightarrow S = (6\hat i - 5\hat j + 3\hat k) \ m$. The work done will be $J$.