Question

A moving train is brought to rest within 20 seconds by applying brakes. Find the initial
velocity, if the retardation due to brakes in 2 m/s?.​

Answer 1

Explanation:

v = u + at

0 = u - 2 ×20

u =40 m/ s

BY THE Way there should be a = 2m/s²

Answer 2

Given that:

• A moving train is brought to rest within 20 seconds by applying brakes.

To Find:

• What is its initial velocity if retardation is 2 m/s²?

Formula used:

From equation of motion,

• v = u + at

Where,

• v = Final velocity
• u = Initial velocity
• a = Acceleration
• t = Time

We have:

• v = 0
• a = - 2 m/s²
• t = 20 seconds

Finding the initial velocity:

ㅤ↠ㅤv = u + at

ㅤ↠ㅤu = v - at

Putting the values.

ㅤ↠ㅤu = 0 - (- 2)(20)

ㅤ↠ㅤu = - (- 40)

ㅤ↠ㅤu = 40

Hence,

• Its initial velocity is 40 m/s.