Question

A car speed increases from 40 km/h to 60 km/h in 5 seconds. Calculate the acceleration of the car.

Answer 1

Question: A car speed increases from 40 km/h to 60 km/h in 5 seconds. Calculate the acceleration of the car.

Given: A car speed increases from 40 km/h to 60 km/h in 5 seconds.

To Find: Acceleration of the car.

Solution: Acceleration of the car $=1.11ms^{2}$

Step by step Explanation:

$u=\frac{40km}{hr} =\frac{40\times5}{18} =\frac{100}{9} =11.11ms^{-1} \\v=\frac{60}{hr} =\frac{60\times5}{18} =\frac{150}{9} =16.66ms^{-1} \\a=? \: \:\: \:\: \: \: \: t=5sec\\a=\frac{v-u}{t} \\= \frac{16.66-11.11}{5} \\=\frac{5.55}{5} \\=1.11ms^{-2}$

Answer 2

$\bigstar$ Answer:

$\checkmark$ Given:

⇒ A car speed increases from 40 km/h to 60 km/h in 5 seconds

$\checkmark$ To Find:

⇒ Acceleration ( a ) of the car

$\checkmark$ Solution:

We know that,

Acceleration ( a ) is given by the Formula,

$\blue{\boxed{\boxed{\sf a=\dfrac{v-u}{t}}}}$

Given that,

A car speed increases from 40 km/h to 60 km/h in 5 seconds

So,

Initial Velocity ( u ) = 40 km/hr

Final Velocity ( v ) = 60 km/hr

Time ( t ) = 5 sec

Converting

Initial Velocity ( u ) and Final Velocity ( v ) from km/hr to m/s

$\sf km/hr \longrightarrow \ m/s$

$\underline{\sf Simple \ Trick:} \\\\ \sf \ km/hr \times \dfrac{5}{18} \ \longrightarrow \ m/s$

Therefore,

$\implies \sf u=40 \ km/hr$

$\implies \sf u=\dfrac{40 \times 5}{18} \ m/s=11.11 \ m/s$

$\implies \sf v=60 \ km/hr$

$\implies \sf v=\dfrac{60 \times 5}{18} \ m/s=16.66 \ m/s$

So,

$\pink{\implies \sf u=11.11 \ m/s}$

$\red{\implies \sf v=16.66 \ m/s}$

$\orange{\implies \sf t=5 \ s}$

Substituting the above values in the Formula,

We get,

$\blue{\implies \sf a=\dfrac{16.66-11.11}{5} \ m/s^2}$

$\blue{\implies \sf a=\dfrac{5.55}{5} \ m/s^2}$

$\pink{\implies \sf a=1.11 \ m/s^2}$

Hence,

Acceleration ( a ) of the car is 1.11 m/s²

a = 1.11 m/s²