A constant force F acts on a body producing a displacement s that makes an angle θ with the force.
a. (i) Resolve the displacement into components along and perpendicular to the direction of the force and hence derive an expression for the work done by the force in terms of F, s and θ.
b. (ii) From the expression obtained in part (i), explain how work can take positive, negative or zero values depending on θ.
c. (iii) State one common example each to illustrate positive, negative and zero work, mentioning the approximate angle between force and displacement in each case.