Question

a car is retarded by applying brakes at the rate of 2m per second square. it is stopped in 10 secs. find initial velocity

Answer 1

a= -2 m/s²
t= 10 secs
According to 1st equation of motion,
v=u+at
So,
0=u+(-2*10)
or, u=2*10  =20 m/s

Answer: 20 m/s

Answer 2

Hi there !!

Acceleration = a= -2 m/s²
Time = t= 10 secs
Initial velocity = u
Final velocity = v = 0

equation of motion :-

v = u+at
So,

0 = u+(-2 x 10)

u = 2 x 10
= 20 m/s

Initial velocity = 20 m/s