Nahed weighs 55 kg, she uses her scooter of mass 5 kg to go to her nearby friend's house. Her speed upon arriving is 15 m/s.   a. Calculate the work done by the brakes to stop the scooter.   b. What is the magnitude of the breaking force, if the scooter comes to a rest after 3 m

A puck of mass 0.170 kg slides across ice in the positive x-direction with a kinetic friction coefficient between the ice and puck of 0.150. If the puck is moving at an initial speed of 12.0 m/s, (a) what is the force of kinetic friction? (b) What is the acceleration of the puck? (c) How long does it take for the puck to come to rest? (d) What distance does the puck travel during that time? (e) What total work does friction do on the puck? (f) What average power does friction generate in the puck during that time? (g) What instantaneous power does friction generate in the puck when the velocity is 6.00 m/s? (See Sections 2.5, 4.6, 5.1, and 5.6.)

3. A skier of mass m starts from rest at the top of a frictionless, snow covered hill angled at 0 above the horizontal. The ski down the hill a distance du and onto a flat parking lot. The coefficient of friction between the cement in the parking lot and the skis is μk. They move along the parking lot a distance dR before stopping. This is drawn below a. Derive an equation for the skier's speed at the bottom of the hill.. b. Derive an equation for dr, the distance the skier slides into the parking lot before stopping. c. If there was a little friction between the snow and skies, explain how your solution would change. You should not re-solve the problem, just describe how your methods would need to change. dH e dR

1. Sam, whose mass is 75 kg, takes off across level snow on his jet-powered skis. The skis have a thrust of 200 N and a coefficient of kinetic friction on snow of 0.10. Unfortunately, the skis run out of fuel after only 10 s. A. What is Sam’s top speed? B. How far has Sam traveled when he finally coasts to a stop?