Question

Find the initial velocity of a car which is stopped in 10 seconds by applying brakes the retardation due to brakes is 2.5m/s2

Answer 1

initial velocity (u) =?<br />final velocity (v)= 0 because car is stopped<br />time = 10 sec<br />v=u+at <br />so u= v - at<br />u= 0 -(-2.5*10)<br />u= 0 + 25<br />u= 25 m/s <br />

Answer 2

Given:-

• Final velocity,v= 0m/s
• Time taken to stop ,t = 10s
• Retardation ,a = -2.5m/s²

To Find:-

• Initial velocity ,u ?

Solution:-

According to the Question

It is given that a car which is stopped in 10 second by applying breaks and the reterdiation due to Break is 2.5m/s².

Using 1st equation of motion

• v = u + at

Where,

• v is the final velocity
• a is the acceleration
• u is the initial velocity
• t is the time taken

Putting the value we get

→ 0 = u + (-2.5) × 10

→ -u = -25

→ u = 25m/s

Hence, the initial velocity of the car is 25m/s²

$\: \: \: \: \: \:$$\huge\fbox{→25m/s²}$