Question

The area of the wheel of a car is 1.54m^2, what is the circumference of the wheel?​

Answer 1

4.4 m

Explanation:

Area of the wheel of a car= 1.54 m²

Area of a circle=
`\pi r^(2)`

1.54= 3.14 x r²

r²=
`(1.54)/(3.14)`

r²= 0.49

r= 0.7 m

Circumference of the wheel=
`2\pi r`

= 2 x 3.14 x 0.7

= 4.4 m

∴ the circumference of the wheel is 4.4 m

Answer 2

Let the number of revolutions made by a circular wheel be n and the radius of circular wheel be r.

Given that, area of circular wheel
=
1.54

m
2


⇒
π
r
2
=
1.54



[
∵
a
r
e
a

o
f

c
i
r
c
u
l
a
r
=
π
r
2
]


⇒
r
2
=
1.54
22
×
7
⇒
r
2
=
0.49


r
=
0.7
m


So, the radius of the wheel is 0.7 m.

Distance travelled by a circular wheel in one revolution

= Circumference of circular wheel

=
2
π
r


=
2
×
22
7
×
0.7


=
22
5
=
4.4
m


[
∵
c
i
r
c
u
m
f
e
r
e
n
c
e

o
f

a

c
i
r
c
l
e
=
2
π
r
]


Since, distance travelled by a circular wheel = 176 m

∴

N
u
m
b
e
r

o
f

r
e
v
o
l
u
t
i
o
n
s


=
T
o
t
a
l

d
i
s
t
a
n
c
e
D
i
s
t
a
n
c
e

i
n

o
n
e

r
e
v
o
l
u
t
i
o
n
=
176
4.4
=
40


Hence, the required number of revolutions made by a circular wheel is 40.