Question

A body moving with a certain velocity is brought to rest in 8 seconds. Calculate its initial velocity if the body was decelerated by 2 m/s^2.

Answer 1

Final velocity =0
Time taken =8s
Acceleration = -2m/s^2
Let initial velocity be u

Using acceleration formula
a=(v-u)/t
-2 = (0-u)/8
-16 = -u
u= 16


So, the inital velocity was 16m/s

Answer 2

v=0
u =?
t= 8sec 
a = - 2 m/s²

o = u - 2 x 8 

u = 16 m/s