Question

A car which is moving with 20 m/s velocity comes to rest in 5
seconds by applying brake calculate its acceleration.​

Answer 1

Solution :-

• Initial velocity of the car = 20 m/s

• Final velocity of the car = 0 m/s ( comes to rest )

• Time taken by the car to come to rest = 5 s

A the car is moving with uniform acceleration throughout it's motion we can use the first kinematic equation in order to solve this question

As per the formula ,

⟹ v = u + at

here ,

• v = final velocity

• u = initial velocity

• a = acceleration

• t = time taken

Now let's substitute the given values in the above equation ,

⟹ 0 = 20 + a x 5

⟹  5a = - 20

⟹ a = - 20 / 5

⟹ a = - 4 m/s ²

Here the negative sign denotes retardation

The acceleration of the car is 4 m/s ²