A 2100 car starts from rest at the top of a 5.0m long driveway that is sloped at 20 degrees with the horizontal. If an average friction force of 4000N impedes the motion find the speed of the car at the bottom of the driveway.

Answer 1

h = 5*sin20 = 1.71 m.
PE = mgh = 2100*9.8*1.71 = 35,192 J.
KE = PE-Fk*d.
0.5mV^2 = 35192 - 4000*5
1050V^2 = 15,192
V^2 = 14.47
V = 3.80 m/s.