Question

A car accelerates uniformly from 36 km/h to 108 km/h in 10 s. The acceleration produced by car is
A)20 m/s²
B)3 m/s²
C)2 m/s²
D)30 m/s²

Answer 1

Answer:

• (c) 2m/s² is the required acceleration.

Explanation:

According to the Question

It is given that,

• Initial velocity ,u = 36km/h
• Final velocity ,v = 108km/h
• Time taken ,t = 10s

We have to calculate the acceleration of the car .

Firstly we change the unit here

Conversion of Unit :

→ Initial velocity = 36×5/18 = 10m/s

→ Final Velocity = 108×5/18 = 30m/s

Now,

We know that acceleration is defined as the rate of change in velocity at per unit time.

• a = v-u/t

On substituting the value we get

↠ a = 30-10/10

↠ a = 20/10

↠ a = 2m/s²

• Hence, the acceleration of the car is 2m/s²

Answer 2

Initial velocity (u) = 36 Km/hr = 10 m/s

Final velocity (v) = 108 Km/hr = 30 m/s

Time Taken (t) = 10 sec

By First equation of motion

$\sf \: v = u + at \qquad \displaystyle \boxed{ \bf \: a = \frac{v - u}{t} }$

$\sf \: a = \dfrac{30- 10}{10} = \dfrac{20}{10} = 2m {s}^{ - 2}$

Option (c) 2 m/s is correct.