Which of the following is a scalar quantity?

$A$ force $F = (5\hat{i} + 3\hat{j}) \ N$ acts on an object,causing a displacement of $r = (2\hat{i} - 1\hat{j}) \ m$. Calculate the work done in $J$.

$A$ body of mass $20 \ kg$ is at rest. $A$ force of $5 \ N$ is applied to it. Find the work done in the first second.

$A$ force of magnitude $30\, N$ acting along $\hat{i} + \hat{j} + \hat{k}$ displaces a particle from point $(2, 4, 1)$ to $(3, 5, 2)$. The work done during this displacement 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:

If $\vec{F}$ and $\vec{S}$ are force and displacement respectively,and the work done by them is zero,then: