Question

A bus moving along a straight line at 20mls undergoes an acceleration of 4mls .After 2 seconds ,it's speed will be a)8M/a b) 12m/s c) 16m/s d) 28m/s

Answer 1

Answer:

☆ Given ☆

$\textsf{Initial velocity of the bus at straight line = 20m/s}$

$\textsf{Acceleration undergoes = 4 m/s}$

$\textsf{Speed after 2 seconds}$

☆ To find ☆

$\textsf{What is the speed after 2 seconds}$

☆ Taken ☆

Use the first equation of motion:

$\huge{\boxed{v=u+at}}$

Where,

v = Final velocity

u = Initial velocity

a = Acceleration

t = Time

☆ Concept ☆

Using the first equation of motion we can solve this question . By , this we will get the final velocity.

☆ Calculation ☆

$\implies\:\:\:\:\:\:\:\:\:\:\:\:{Taken,v=u+at}$

$\implies\:\:\:\:\:\:\:\:\:\:\:\:{v=20m/s+(4m/s×2s)}$

$\implies\:\:\:\:\:\:\:\:\:\:\:\:{v=20m/s+8m/s}$

$\implies\:\:\:\:\:\:\:\:\:\:\:\:{v=28m/s}$

☆ Answer ☆

So , the speed after 2 seconds is 28 m/s .

Or option (d) is the correct option .

☆ Extra information ☆

Second equation of motion:

$v=ut+\frac{1}{2}at²$

Third equation of motion:

$Vf = Vi+at$