As per question,
u = 83m/s
a = -3m/s2
t = 2 s
v = ?
v = u + at
v = 83 + (-3) x 2
v = 83 - 6 = 77m/s Ans.....
To find the time after which it stops i.e. v becomes 0.
again v = u + at
0 = 83 - 3 x t
t = 83/3 = 27.66s Ans....
To find the distance travelled before coming to rest,
v2 = u2 + 2ax ( also x = ut + 1/2 at2 can be used)
02 = 832 + 2(-3) x
x = - 832/-6 = 1148.16m Ans......