Question

A bus was moving with speed of 54km/h. On applying brakes it stopped in 8 seconds. Calculate the acelerion and distance travelled before stopping.

Answer 1

initial velocity=54x5/18=15m/s
final velo= 0
time=8 s
a=?
s=?
solution: v=u+at
              0  =15+a(8)
              -(15)  =8a
              a     = -15/8m/s2     (- sign indicates retardation)

            v2 -u2= 2as
            (0)2- (15)2= 2(-15/8)s
                   -225 =-15/4 s
                   -225x4/-15 =s
                      60=s
                    s =60 m