A 2.0kg block is placed on a smooth horizontal surface. A horizontal force that varies with position according to F(x)=5xN (where x is in metres measured from the starting point) begins to act on the block from rest at x=0 and continues until the block reaches x=4m.
a. (i) Write, without evaluation, the integral that represents the work done by this force while the block moves from x=0 to x=4m.
b. (ii) Evaluate the work done numerically.
c. (iii) Determine the speed of the block after it has moved through 4m.