The force $F$ acting on a body moving in a circle of radius $r$ is always perpendicular to the instantaneous velocity $v$. The work done by the force on the body in one complete rotation is:

If a force $\vec F = 4\hat i + 5\hat j$ causes a displacement $\vec s = 3\hat i + 6\hat k$,the work done is:

$A$ cubical vessel of height $1 \,m$ is full of water. What is the amount of work done in pumping water out of the vessel (in $\,J$)? (Take $g = 10 \,m \,s^{-2}$)

$A$ force of $(4\hat i + \hat j + 3\hat k) \, N$ acts on a body,causing its displacement from $(3\hat i + 2\hat j - 6\hat k) \, m$ to $(14\hat i + 13\hat j + 9\hat k) \, m$. Calculate the work done in $J$.

$A$ cyclist comes to a skidding stop in $10 \,m$. During this process,the force on the cycle due to the road is $200 \,N$ and is directly opposite to the motion. How much work does the road do on the cycle?

$A$ force $\vec{F} = (5 \hat{\imath} - 2 \hat{\jmath} + 3 \hat{k}) \text{ N}$ acts on a body of mass $2 \text{ kg}$ and displaces it from position $\vec{r_1} = (3 \hat{\imath} + 2 \hat{\jmath} - \hat{k}) \text{ m}$ to $\vec{r_2} = (6 \hat{\imath} - \hat{\jmath} + 4 \hat{k}) \text{ m}$. The work done is: (in $\text{ J}$)