a
(a)Work done = Area covered in between force displacement curve and displacement axis
= Mass \(\times\) Area covered in between acceleration-displacement curve and displacement axis.
= \(10 \times \frac{1}{2}(8 \times {10^{ - 2}} \times 20 \times {10^{ - 2}})\)
= \(8 \times {10^{ - 2}}\,J\)