Question

Car moving along a straight line at a speed of 54 km/h stop in 5 sec after brakes are applied. (A) find the accelaration (b) plot graph of speed vs time (c) find distance covered by car before brakes are applied

Answer 1

u=54km/h=15m/s
v=0 m/s
t=5s
v=u+at
(v-u)/t=a
a=(0-15)/5
a=-3m/sec square

v^2=u^2-2as
0=225-2×3s
-225=-6s
s=225/6=37.8