Question

A force of 100 N displacement an object through 0.2 m and does work of 10 joules. What is the angle between the force and displacement?

Answer 1

As the work done is the dot product of force and displacement, so if $\theta$ be the angle between them, $W=Fd\cos \theta$

or $10=100\left(0.2\right)\cos \theta$ or $\cos \theta =1/2=\cos {60}^o$

or $\theta ={60}^o$