Question

A body moving with a velocity of 80m/s is brought to rest in 5second. Calculate the raterdation

Answer 1

V=80m/s
t=5 sec
we know that

a=V/t

=80/5

=16m/s
in quea they asked about retardation
so retardation is -16

hope my answer is correct

Answer 2

initial velocity=80(u)
t=5
final velocity=0(v)
a=to be calculated(acceleration or retardation)
we know that ,
v=u+at

now putting the values in this formula
we get,

0=80+a×5
-80÷5=a
-16 =a


thus the retardation is -16