Find the initial velocity of the car which is stopped in 10 sec by applying brakes .The retardation due to brakes is 2.5m/sec sq.....

Final vel. : 0 initial vel. : ? t : 10sec retar. : 2.5 m/s2 V=U+AT O = U+ 2.5 *10 U=25 m/s

let final velocity be o and initial velocity be u
time = 10 sec
acceleration = -2.5m/s²
according to first formula
v = u + at
where v = 0
u = ?
a = -2.5m/s²
t = 10 sec
v = u + at
0 = u + (-2.5) * 10
0 = u - 25
u = 25 m/s
 

Here the initial velocity is 25

Using v = u+at formula, initial velocity is 25m/s
 

initial velocity , u=x
final velocity,v=0
time,t=10
​retardation due to brakes,a= 2.5m/s2
​v=u+at
0=x+(-2.5)(10)
-x=-25
x=25m/s