dynamics
posted by umesh on .
the 1500 kg automobile is travelling up the 20 degree inclined at a speed of 6 m/s , if the driver wishes to stop his car in a distance of 5m , determine the frictional force at the pavement which must be supplied by the rear wheels.

V^2 = Vo^2 + 2ad.
a = (V^2Vo^2)/2d.
a = (036)/10 = 3.6 m/s^2.
Fk = m*a = 1500 * 3.6 = 5400 N. Acting
in opposite direction of motion. 
CORRECTION:
PE = KE.
h = 5*sin20 = 1.71 m.
mg*hFk*d = 0.5m*V^2.
1500*9.8*1.71Fk*5 = 0.5*1500*6^2
25,1375Fk = 27,000
5Fk = 2700025,137 = 1863
Fk = 373 N. = Force of kinetic friction.