Car speed=160km/hr speed camera 120m ahead final speed at camera =70km/hr calculate the deceleration of the ca

Question

Car speed=160km/hr speed camera 120m ahead final speed at camera =70km/hr calculate the deceleration of the ca

Answer 1

Ok, here's how you do it.

You know that

A=(Vf-Vo)/t

and

x = (Vf+Vo)*t/2

solving for t

t = 2x/(Vf+Vo)

then substituting in the first equation

a = (Vf-Vo)(Vf+Vo)/(2x) = (Vf^2-Vo^2)/(2x)

where

A = acceleratoin

Vf = Final velocity

Vo = initial velocity

x = distance

all this is supposing constant acceleration, then substituting

a = ((70km/h)^2-(160km/h)^2)/(2*120m)

a = -86250 km/h^2 = -6.47m/s^2

hope this helps.