Question

If an object is moving its initial velocity is72km/h and after 5 sec the velocity of the objects becomes 34km/h due to applying brakes. how much the acceleration will produce

Answer 1

Given,
u=72kmph
v=34kmph
t= 5s
acceleration=v-u/t
=38/5
=7.6
a=-7.6

Answer 2

Here given that:
u=72km/h , v=34km/h , t=5sec
we know that the first equation of motion is :
v = u + a.t
34 = 72 + a.5
5a = - 38
a = - 7.6 m/sec sq.
Here negative sign shows that acceleration is decreasing with time ...