Question

a train travelling at a 10m/s accerlerates to 20m/s in 5 seconds. what is its accerlation

Answer 1

To solve this question, Let's see some basic concepts :
Distance : It is the length of the path.
Displacement : It is the shortest line segment joining initial and final points.
Speed : Distance covered in unit time
Velocity : Displacement travelled in unit time.
Acceleration is the rate of change of velocity per unit time. When we say a body has accelerated, it means that it changed its velocity over a period of time.

a = change in velocity/time = v - u /t

Given

$\sf \: {Initial \: velocity }(u) \: = 10m {s}^{ - 1} \\ \\ \sf \: {final \: velocity } (v)\: = 20m {s}^{ - 1} \\ \\ \sf \: time(t) \: = 5s$

Now,

$a = \frac{v - u}{t} \\ \\ \implies \: a \\ \implies\frac{20 - 10}{5} \\ \implies \frac{10}{5} \\ \implies \: 2m {s}^{ - 2}$

Therefore, Acceleration of the train is 2m/s²

Answer 2

Given info :

Initial velocity of the train ( u ) = 10 m/s .

Final velocity of the train ( v ) = 20 m/s .

Time taken to accelerate ( t ) = 5 s .

We know that acceleration is the rate of change of velocity per unit time .

We also know that the rate of change of velocity is the change in the final velocity and the initial velocity of the body .

Rate of change of velocity = v - u .

Acceleration is just rate of change of velocity in unit time .

Let the acceleration be A .

$A=\dfrac{v-u}{t}\\\\\implies A=\dfrac{20m/s-10m/s}{5s}\\\\\implies A=\dfrac{10m/s}{5s}\\\\\implies A=2m/s^2$

The acceleration of the train will be 2 m/s² .