Question

A car moving
with a speed of 20m/s brought to rest in 5sec calculate the accelaration​

Answer 1

Answer:

Given:

• A car moving with a speed of 20 m/s brought to rest in 5 sec.

Find:

• Calculate the acceleration.

Know terms:

1. Initial velocity = (u)
2. Final velocity = (v)
3. Time = (t)
4. Acceleration = (a)

Using formula:

☆ ${\sf{\underline{\boxed{\red{\sf{v = u + at}}}}}}$

Calculations:

⇒ $\bold{0 = 20 + a(5)}$

⇒ $\bold{a = \dfrac{-20}{5}}$

⇒ $\bold{-4 \: m/s^2}$

⇒ $\bold{4 \: m/s^2}$

Therefore, 4 m/s² is the acceleration.

Note:

• (-ve) shows retardation.

Answer 2

Answer:

-4 m/s²

Explanation:

Given :

• Initial velocity = u = 20 m/s

• Final velocity = v = 0 m/s

• Time taken = t = 5 seconds

To find :

• Acceleration of the car

Acceleration = (v-u) / t

Acceleration = (0-20)/5

Acceleration = - 20/5

Acceleration = - 4 m/s²

The acceleration of the car is equal to - 4 m/s² which means the car is reducing its speed by 4 m/s every second