Question

a moving train isbrought to rest within 20 seconds by appying breaks , find the initial velocity if the retardation due to breaks is 2m/s²​

Answer 1

Explanation:

Given:

Final velocity v = 0

Time taken t = 20 s

Acceleration a = -2 m/s2

From the equation v = u + at, we have

u = v - at

→ u = 0 - (-2) × 20

→ u = 40 m/s2

Answer 2

Given :-

A moving train brought to rest within = 20 sec

The retardation due to breaks = 2 m/s²​

To Find :-

The initial velocity.

Analysis :-

Initial velocity = Final velocity - (Acceleration × Time)

Solution :-

We know that,

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

Given that,

Final velocity (v) = 0  m/s

Time taken (t) = 20 s

Acceleration (a) = -2 m/s²

Using 1st Equation of Motion,

$\underline{\boxed{\sf u=v-at}}$

Substituting their values,

$\sf \longrightarrow u = 0 - (-2) \times 20$

$\longrightarrow \sf u=40 \ m/s^{2}$

Therefore, the initial velocity is 40 m/s²