Question

A brakes of car van produce acceleration of -10m/s square . If speeding is brought to rest in 3s calculate initial velocity of the car

Answer 1

Solution :-

Now as given :-

Acceleration = - 10 m/s²

Time = 3 sec

Final velocity = 0

Now as we have got the motion equation :-

→ v = u + at

Now we will replace our values :-

→ 0 = u + (-10)(3)

→ 0 = u - 30

→ u = 30

So the initial velocity = 30 m/s

Answer 2

Answer:-

Explanation:

Known Term :-

u = Initial Speed

t =  Time taken

v = Final Speed

a = Acceleration

Given :-

Final Speed  of car, v = 0 (because car comes on rest)

Acceleration by the car, a = -10 m/s²

Time taken by the car, t = 3 seconds

To calculate :-

Initial velocity of the car

Formula to be used :-

v = u + at

Solution:-

Putting all values, we get

v = u + at

⇒ 0 = u + (-10 × 3)

⇒ 0 = u - 30

⇒ u = 30 m/s

Hence, Initial velocity of the car is 30 m/s.