Question

the diameter of the wheel of a car is 70 cm. How many revolutions will it make to travel one kilometer?

Answer 1

Answer:

455

Step-by-step explanation:

We know circumference= 2πr= πd

=3.14× 70 cm= 219.8 cm

revolutions required= 1 km/219.8 cm

= 100000cm/219.8cm

=455 approx

Answer 2

$\sf\large\underline{\underline{\red{\sf Question }}}:$

• The diameter of the wheel of a car is 70 cm. How many revolutions will it make to travel one kilometer?

$\sf\large\underline{\underline{\red{\sf Steps \;to\;solve}}}:$

• Firstly we find the circumference of the wheel by using its diameter. So that we get distance covered in 1 revolution.
• Then to find the numbers of the number of revolutions we will divide total distance by distance covered in one revolution.

$\sf\large\underline{\underline{\red{\sf Solution}}}:$

We know,

$\green\bigstar\boxed{\sf Circumference_{circle}= 2\pi r \;\;\green{or}\;\;\pi d}$

Where,

• r is radius of the circle .
• d is diameter of the circle.

$\large\purple{\underline{\large \mathfrak{Subsituting\;the \;values\; ;}}}$

$\longmapsto\sf Circumfernce_{circle}= \pi\times 70\\\\\longmapsto\sf Circumfernce_{circle}= \dfrac{22}{{7}}\times {70}\\\\\longmapsto\sf Circumfernce_{circle}= 220 cm.$

Here we got the circumference of the wheel that is 220 cm. It means that 1 revolution can cover 220 cm of distance.

We have to number of revolutions wheel will make in 1 km. { 1 km = 100000 cm }

$\longmapsto\textbf{No. of revolutions} = \sf \dfrac{100000}{22}\\\\\longmapsto\textbf{No. of revolutions} = 454.5$

Hence,

• Wheel of car will make 454.5 revolutions to travel 1 kilometer.