Question

What will be the speed of a bus whose speed increases from 60 m/s to 100 m/s in 5s?
1. 80 m/s²
2. 32 m/s²
3. 30 m/s²
4. 8 m/s²

Answer 1

Correct Answer - Option 4 : 8 m/s²

Concept:

• Equation of motion: The mathematical equations used to find the final velocity, displacements, time, etc of a moving object without considering force acting on it are called equations of motion.
• These equations are only valid when the acceleration of the body is constant and they move on a straight line.

There are three equations of motion:

V = u + at

V2 = u2 + 2 a S

\({\text{S}} = {\text{ut}} + \frac{1}{2}{\text{a}}{{\text{t}}^2}\)

Where, V = final velocity, u = initial velocity, s = distance travelled by the body under motion, a = acceleration of body under motion, and t = time taken by the body under motion.

Calculation -

Given: V = 100m/s, u = 60 m/s, t = 5 Seconds

To answer this numerical we will be using the equation of motion: 

​So, putting the given value in equation

V = u + a t 

100 = 60 + a × 5 

100 - 60 = 5 a  

40 = 5 a

a = 8 m/s²

The acceleration of the car is 8 m/s².