$A$ body of mass $m$ moves in a circle of radius $r$ with a constant speed $V$. $A$ force of $mV^2/r$ acts towards the center of the circle. Find the work done by this force when the body covers half the circumference of the circle.

$A$ force of $(-\,1, \,2, \,3) \,N$ is applied to an object,causing a displacement of $4 \,m$ along the $X$-axis. Calculate the work done by the force on the object. (in $,J$)

$A$ sphere of mass $m$ is tied to one end of a string of length $l$ and rotated through the other end along a horizontal circular path with speed $v$. The work done in a full horizontal circle is

Consider a particle on which constant forces $F_{1}=\hat{i}+2 \hat{j}+3 \hat{k} \text{ N}$ and $F_{2}=4 \hat{i}-5 \hat{j}-2 \hat{k} \text{ N}$ act together, resulting in a displacement from position $r_{1}=20 \hat{i}+15 \hat{j} \text{ cm}$ to $r_{2}=7 \hat{k} \text{ cm}$. The total work done on the particle is:

$A$ force of $(5\hat i + 6\hat j - 7\hat k) \, N$ is applied to a body of mass $10 \, kg$,causing it to displace from position $(4\hat i - 2\hat j + 5\hat k) \, m$ to $(8\hat i + 6\hat j - 3\hat k) \, m$. Calculate the work done in $J$.

$A$ man of mass $50 \ kg$ carrying a load of $10 \ kg$ reaches the top of a building in $4 \ minutes$. The work done by the man is $6 \times 10^4 \ J$. If he reaches the top in $2 \ minutes$,the work done by the man will be: