Question

how many time a wheel of radius 28cm must rotate to cover a distance of 352m (take pi 22_7​

Answer 1

first we have to find the circumference,

formula= 2πr

= 2×22/7×28

= 2×22×4 ( I have been reduced 7 and 28 as they go in 7 times table

= 44×4=176circumference

hope this is right

Answer 2

Given :

• Radius of a wheel = 28 cm
• Distance to be covered = 352 m

To find :

• Number of times the wheel must rotate to cover a distance of 352 m

Solution :

Firstly, we will find the circumference of the wheel.

Using formula,

Circumference of the circle = 2πr

where,

• Take π = 22/7
• r = radius of the circle

Substitute the given values,

⇒ Circumference = 2 × 22/7 × 28

⇒ Circumference = 2 × 22 × 4

⇒ Circumference = 176

Circumference of the circle = 176 cm

Now, we will convert the circumference from cm into m.

∵ Units should be same.

As we know,

1 cm = 0.01 m

Divide the value by 100 to convert it from cm into m.

⇒ 176/100

⇒ Circumference of the circle = 1.76 m

Distance covered = Circumference × No. of rotations

⇒ 352 = 1.76 × No. of rotations

⇒ 352/1.76 = No. of rotations

⇒ 200 = No. of rotations

★ No. of times the wheel must rotate to cover a distance of 352 m = 200