Driving in a car with a constant velocity of 11.4 m/s you suddenly see an obstacle ahead. Immediately applying the brakes the car slows with an acceleration of 3.80 m/s2.

Question

(i) Calculate the stopping distance of the car, and
(ii) the time taken to stop.

Answer 1

Do step (ii) first.
(ii) Vo = a*t
t = 11.4/3.80 seconds

(i) Stopping distance = (avg. velocity)*t
= (Vo/2)*(Vo/a) = Vo^2/(2 a)

You could do question (i) first using
Vo^2 = 2 a X
but I find it more difficult to remember that formula.

Answer 2

thanks alot :D i got 3s for t for part 2!! nd i got 17.1s for part1 is dat correct??

Answer 3

Yes!

Answer 4

post it.