Question

A road roller takes 500complete revolutions to move once over to level a road. Find the area of the road if the diameter of a road roller is 84cm and length is 1 m.

Answer 1

Answer: 1320m²

Step-by-step explanation: area of a hollow cylinder= 2πrh

radius of the road roller= 84/2= 42cm

let pi= 22/7

=2*22/7*42*100(length = height)

= 26400

26400*500(times)

= 13200000cm²

1cm²= 0.0001m²

= 1320m²

Answer 2

Given :

• Diameter of a road roller = 84 cm
• Length = 1 m
• Road roller takes 500 complete revolution to move once over to leave a road.

To find :

• Area of the road

According to the question,

⇝ Radius = 84 ÷ 2 = 42 cm

Note :

We have change 42 cm into m. So, the value is 0.42 m

$\sf : \implies{Curved \: surface \: area \: of \: cylinder = 2 \pi rh }$

$\sf : \implies{2 \times \dfrac{22}{7} \times 0.42 \: m \times 1 \: m}$

$\sf : \implies { \dfrac{18.48}{7} \: {m}^{2} }$

${ \underline{ \boxed { \bf \red{ : \implies{2.64 \: {m}^{2} }}}}} \: \bigstar$

So, the area of road in one revolution is 2.64 m².

Now,

➞ Area of road in 500 revolution = 2.64 × 500

➞ Area of road in 500 revolution = 1320 m²

$\therefore {\underline{ \sf{Area \: of \: road \: in \: 500 \: revolution \: is \: 1320 \: {m}^{2} }}}$