A body constrained to move along the z -axis of a coordinate system is subject to a constant force F given by vec(F) =(-hat(i)+2hat(j)+3hat(k))N where hat(i),hat(j),hat(k) are unit vectors along the x, y and z-axis of the system respectively . What is the work done by this force in moving the body a distance of 4 m along the z- axis?

A body constrained to move along the z -axis of a coordinate system is

1.	A body constrained to move along the z -axis of a coordinate system is subject to a constant force F given by vec(F) =(-hat(i)+2hat(j)+3hat(k))N where hat(i),hat(j),hat(k) are unit vectors along the x, y and z-axis of the system respectively . What is the work done by this force in moving the body a distance of 4 m along the z- axis?
Answer» Solution :`W =VEC(F).vec(d)` `=(hat(i)+2hat(j)+3hat(K)).(4hat(k))` =12 J