Question

Find the initial velocity of a car that is stopped in 10 second by applying brakes retardation due to break is 2.5 M per second square

Answer 1

hey your ans is here
---------
u=?
v=0(since it comes to rest after moving a distance)
t=10
r=2.5 so acceleration will be -2.5
a=-2.5
now apply the formula
a=v-u/t
-2.5=0-u/10
-2.5×10=-u
u(initial velocity)=25m/s
--------
:-)

Answer 2

u=0
v=0
t=0
r=2.5
a=-2.5

by applying the third formula,
a=v-u/t
=-2.5×10=-u
u=(initial velocity)=25m/s (Ans)