Question

The diameter of the wheel of a car is 70cm. How many revolutions will it make to travel 9 km



Answer please​

Answer 1

Question:-

The diameter of the wheel of a car is 70cm. How many revolutions will it make to travel 9 km?

Answer:-

• The total number of revolutions is 4090

To find:-

• Number of revolutions

Solution:-

Diameter of car wheel (d) = 70 cm

We know the radius is half the diameter.

Thus,

• The radius(r) is $\frac{70}{2} = 35 \: cm$

We can calculate the distance in one revolution by determining the circumference of wheel.

$\boxed{ \pink { \large{circumference = 2\pi \: {r}^{2} }}}$

$\large{ : \implies \: circumference = 2 \times \frac{22}{7} \times 35}$

$\large{ : \implies \: circumference = 2 \times 22 \times 5}$

$\large{ : \implies \: circumference = 220 \: cm}$

We will divide it by 10,000 to convert it into km

$\large{\implies \: \frac{220}{10000} \: km}$

Hence,$\large{ \frac{220}{10000} \: km}$is covered in 1 revolution.

Then, we will divide the given distance by distance covered in 1 revolution to find the number of revolutions .

$\implies \: \frac{9}{220} \times 100000 = 4,090.90$

∴The total number of revolutions is 4090