After the inelastic collision of the two carts, where they fuse into an object with double the mass of the original cart, there is a frictional section of the track to slow the carts to a stop over 20 meters. The amount of work due to friction and the frictional force exerted to stop both carts will be calculated. This equation is used for calculating the work due to friction: W. =f. . co50 . Ax Since the carts are moving on a flat horizontal surface, 0 =180' and cos 180*= -1, and it is stated that the carts are brought to a stop over 20 meters, so Ax=20m: W.=-f. . 20m f