What is the average force required of the brakes in a 1200 kg car in order for it to come to rest from 60kmh–1 in a distance of 150m?

Question

anonymous · Answer

Given:
m = mass = 1,200 kg
vo = initial velocity = 60 kph = 16.667 m/sec
vf = final velocity = 0 (it come to rest)
s = distance = 150m
a = acceleration/deceleration = ?
F = force = ?

vf^2 = vo^2 + 2as
0 = (16.667)^2 + (2*a*150)
-300a = 277.778
a = 277.778/-300
a = -0.926 m/sec^2 (negative acceleration because it is coming to stop/rest)

F = ma
F = 1,200kg x 0.926 m/sec^2
F = 1,111.11 Newtons (answer)

anonymous · Answer

Thank you so much!

mathslover · Answer

first of all good work @nitinz570 I will request you to mention the link also: http://au.answers.yahoo.com/question/index?qid=20110509050436AAvB8tG

mathslover · Answer

From which you have taken the answer ..

anonymous · Answer

i have written myself....understand

mathslover · Answer

sorry nitin you are wrong.. that link contains exact ditto soln