Which of the following is a scalar quantity?

$A$ force $\vec F = 2\hat i - 3\hat j + 7\hat k \text{ (N)}$ acts on a particle which undergoes a displacement of $\vec S = 7\hat i + 3\hat j - 2\hat k \text{ (m)}$. Calculate the work done by the force in $J$.

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

$A$ body of mass $8 \ kg$,under the action of a force,is displaced according to the equation $s = \frac{t^2}{4} \ m$,where '$t$' is the time. Find the work done by the force in the first $4 \ s$. (in $J$)

$A$ particle of mass $m$ is projected with speed $u$ at angle $\theta$ with the horizontal from the ground. The work done by gravity on it during its upward motion is ..........

$A$ string is used to pull a block of mass $m$ vertically up by a distance $h$ at a constant acceleration $\frac{g}{3}$. The work done by the tension in the string is ..............