Question

Find the initial velocity of a car which is stopped in 10 second by applying breaks . The reterdiation due to Break is 2.5m/square

Answer 1

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.

Answer 2

Given :-

Time = 10 sec

Retardation 2.5 m/s²

To Find :-

Initial velocity

Solution :-

We know that

a = v - u/t

Since, it come at rest. So, final velocity is 0

-2.5 = 0 - u/10

-2.5 = -u/10

-2.5 × 10 = -u

-25 = -u

25 = u

Know More :-

v = u + at (1st equation)

s = ut + 1/2 × at² (2nd equation)

v² - u² = 2as (3rd equation)