Question

A car moving with constant acceleration was found to be having a speed of 36 km/hr at certain point of time. After 2 seconds it's speedometer showed 54 km/hr. what is its acceleration?

Answer 1

Given:-

• Initial velocity ,u = 36km/h = 36×5/18= 10m/s
• Final velocity ,v = 54km/h = 54×5/18= 15m/s
• Time taken ,t = 2 s

To Find:-

• Acceleration ,a

Solution:-

According to the Question

We have to calculate the acceleration of the car .Aw we know that acceleration is defined as the rate of change in velocity.

• a = v-u/t

where,

• v is the final velocity
• a is the acceleration
• u is the initial velocity
• t is the time taken

Substitute the value we get

$:\implies$ a = 15-10/2

$:\implies$ a = 5/2

$:\implies$ a = 2.5m/s²

• Hence, the acceleration of the car is 2.5m/s².

Additional Information !!

Some equation of motion are

• v = u +at

• s = ut +1/2at².

• v² = u² + 2as

Here,

v is the final velocity

u is the initial velocity

a is the acceleration

s is the displacement or Distance

t is the time taken

Answer 2

Question:-

• A car moving with constant acceleration was found to be having a speed of 36 km/hr at certain point of time. After 2 seconds it's speedometer showed 54 km/hr. what is its acceleration?

To Find:-

• Find the acceleration.

Solution:-

Given ,

• Initial velocity of the car is 10 m/s

• Final velocity of the car is 15 m/s

• Time taken to cover the distance is 2 seconds.

Now ,

We have to find the acceleration by using first equation of motion:-

$\dashrightarrow\sf \: v = u + at$

$\dashrightarrow\sf \: 15 = 10 + 2a$

$\dashrightarrow\sf \: 2a = 15 - 10$

$\dashrightarrow\sf \: 2a = 5$

$\dashrightarrow\sf \: a = \cancel\dfrac { 5 } { 2 }$

$\dashrightarrow\sf \: a = 2.5 \: { m/s }^{ 2 }$

Hence ,

• Acceleration is 2.5 m/s²