You pull your little sister across a flat snowy field on a sled. Your sister plus the sled have a mass of . The rope is at an angle of 45 degrees to the ground. As you pull with a force of , the sled travels a distance of . How much work do you do

W = 0.7071 F x,  W = 35.355 J

Explanation:

Work is defined

          W = F. d

bold indicates vectors,

           W = F d cos θ

where the angle is between force and displacement.

As the system runs on snow, the friction force is negligible, therefore

           W = F x cos 45

           W = 0.7071 F x

Unfortunately the values ​​of the force and the distance do not appear, suppose that the force is F = 10 N and the distance x = 5m

           W = 0.7071  10  5

           W = 35.355 J

Work is positive because force and displacement go in the same direction

molecules are free to separate from each other and will take on the shape of the container. molecules move completely at random and high speeds. they vibrate in a fixed position and do not move around much. molecules expand to the edge of their container.