Question

A bus moving along a straight line at 20 m per second undergoes an acceleration of 4 m per second square after 2 seconds if speed will be what

Answer 1

Hi.

Here is your answer---

__________________

Given---

Initial Velocity(u) = 20 m/s.
Time(t) = 42 seconds.
Acceleration(a) = 4 m/s²

Let the Final Velocity be v m/s.

Using the Formula,

 Acceleration = (v - u)/t
                  4 = (v - 20)/2
           v - 20 = 4 × 2
                v = 20 + 8
                v = 28 m/s.

Thus, the Final Speed of the Bus after 2 seconds will be 28 m/s.

________________

Hope it helps.

Have a nice day.

Answer 2

Let v be the final speed of the bus.
Since the acceleration is constant, we can use the kinematic equation
v=u+at. v=20+4x2 = 28 m/s