Question

A racing car reaches a speed of 40 m/s. At this instant, it begins a uniform negative acceleration, using a parachute and a braking system, and comes to rest 5.0 s.
(a)Determine the acceleration of the car.

Work:
40m/s x 5s = 200m
(0)^2=(40)^2 +2a(200)
a=-4 m/s^2

(b) How far does the car travel after acceleration starts?

200 m?

Answer 1

No. The distance it traveled was 100m. Averagevelocity during stopping was 1/2 40 * 5

Answer 2

is part (a) right, then? a= -4m/s^2

Answer 3

Part a should be:

40m/s / 5.0s = 8.0m/s^2

Answer 4

a racing car reaches a speed of 44m/s. at this instandt, it behins a uniform deceleration using a parachute and a braking system, and comes to a rest 4.8s later. Find the acceleration of the car