A 1200 kg car is moving at 95 km/h when the driver notices a deer down the road. He immediately moves his foot toward the brake pedal, taking only 0.50 seconds before the car starts slowing down. The brakes cause a net force of 2400 N (backwards) on the car for 2.0 seconds. The deer then jumps out of the way and the driver lifts his foot off the brake pedal. How far does the car move in the 2.5 seconds starting from when the driver sees the deer?

Question

A 1200 kg car is moving at 95 km/h when the driver notices a deer down the road. He immediately moves his foot toward the brake pedal, taking only 0.50 seconds before the car starts slowing down. The brakes cause a net force of 2400 N (backwards) on the car for 2.0 seconds. The deer then jumps out of the way and the driver lifts his foot off the brake pedal. How far does the car move in the 2.5 seconds starting from when the driver sees the deer? 
Using newtons law.

Damon · Accepted Answer

95 km/hr *1000/3600 = 26.4 m/s in .5 seconds moves 13.2 meters then a = F/m = -2400/1200 = - 2 m/s^2 0 = Vo - a t d = 13.2 + 26.4 t - (1/2) (2) t^2 t = 2 so d = 13.2 + 48.8 = 62 meters d = 13.2 +

Damon · Answer

0 = Vo - a t ignore that line, final speed is not zero and is not needed

James Macdonald · Answer

2+2=4