Question

A force $F$ acts on a body and displaces it by a distance $S$ in a direction at an angle $\theta$ with the direction of force. What should be the angle between the force and displacement to get zero work?

• A. ${90}^o$
• B. $0^o$
• C. ${45}^o$
• D. ${180}^o$

Answer 1

Answer: (A)

${90}^o$

As work is given by formula $FS\cos \theta$ and we know cos has minimum value at an angle of 90 degree that is $cos{90}^o=0$.

Hence work becomes zero when angle is ${90}^o$.