Answer to Question #200462 in Classical Mechanics for mohammad

Question

A force (-4i+2j)AND moves an object from the point p(1,3)m to the point Q(3,8) . the work done by the force is

Answer 1

By the definition of the work done, we have:

$$W=Fd.$$

Let's first find the displacement of the object:

$$d=(3-1)i+(8-3)j=(2i+5j)\ m.$$

Finall, we can find the work done by the force:

$$W=(-4i+2j)\ N\cdot(2i+5j)\ m,$$ $$W=-4 N⋅2 m+2 N⋅5 m=2\ J.$$