The 3220 lb car shown is traveling at 60mph to the right whe

The 3220 lb car shown is traveling at 60mph to the right when the driver puts on the brakes, causing the car to decelerate at a rate of 3 ft/s^2. Determine the total normal force the road exerts on (a) the front wheels and (b) the back wheels.

Solution

m=3220lb

u=60mph=88ft/s

a=-3ft/s²

g=32.174 ft/s²

v=0 as car decelerates

using v²=u² + 2as

we get s=1290.66ft

(a) total normal force on front wheels=mg-ma=3220lb x (32.174-(-3))ft/s² =9692.174 lb.ft/s²

^{(b)9692.174/2=4846.087}