question_answer 11)

A body constrained to move along the Z-axis of co-ordinate  system  is  subject  to  a  constant  ton  where  are unit vectors along the  and Z-axis of the system respectively. What is the war done by this force in moving the body a distance of'4 m along the Z-axis ?  

Answer:

Here, As the body moves a distance of 4 m along Z-axis, so .             .