Question

i want a answer elaborated ​

Answer 1

Answer:

step explanation

Radius =2/diameter

Diameter=70cm

so, radius = 35 cm

Area of cylinder = 2πr

= 2×22/7×35

=2×22×5

=220cm

Answer 2

The Concept

To answer the question, we need to know how to find the perimeter of a circle. The perimeter of a circle is called 'circumference', and to calculate it, the following formula is used:

$\boxed{\bf{2\pi r=\pi d}}$

Wherein, the value of π is 22/7 or 3.14.

Let's find out!

Answer

Given:

• diameter of the bicycle = 70 cm
• distance = 4.4 km = 4400 m = 440000 cm

To find:

• times the wheel would rotate to cover the given distance

Solution:

Let us find the distance that one rotation of the wheel can cover. It is finding the circumference of the wheel. Using the formula to find the perimeter of a circle:

$\sf{\Rightarrow \pi\times 70}$

$\sf{\Rightarrow \dfrac{22}{7}\times 70}$

$\sf{\Rightarrow 22\times 10}$

$\sf{\Rightarrow 220\:cm}$

So, one rotation of the wheel covers 220 cm.

Now, to find how many rotations of this wheel can cover the distance, we need to divide the total distance by the distance covered by the rotation of the wheel, i.e, its circumference.

$\sf{\Rightarrow \dfrac{Total distance}{Circumference\:of\:the\:wheel}}$

$\sf{\Rightarrow \dfrac{440000}{220}}$

$\sf{\Rightarrow 2000}$

Therefore, the wheel would rotate 2000 times to cover the distance of 4.4 km.