A 50.kg sled is subject to a net force of 20N pushing in the direction of the sled's motion as it is over a horizontal surface for a distance of 11m after having started from rest. At this point the sled is released as it starts down a 10 degree incline. The snow is not very deep, and the sled stops after having moved an addictional 35m. What is the work done by friction while the sled is on the incline?
A simple pendulum 2.0m in length, is released with a push when the support string at an angle of 25 degrees from the vertical. If the initial speed of the suspended mass is 1.2 m/s when at the release point, What is the speed at the bottom of the swing? (g=9.8)