Question

The diameter of a roller is 84cm and its length

Answer 1

Answer:

What is the question do we have to find the length

Answer 2

$\bold{\huge{\underline{\underline{\rm{ Correct \: Question :}}}}} \: \:$

The diameter of a radius is 84cm and its length is 120 cm.It take 500 to complete the revolution to move once over a level playground.Find the area of playground in m^2

$\bold{\huge{\underline{\underline{\rm{ Given :}}}}} \:$

Length of roller (h) = 120cm = 1.2 m

Diameter of roller (d )= 84 cm

Radius of roller (r) = 84/2 = 42 cm = 0.42

Solution

Area covered by roller in one revolution

$⟹\text{curved surface area} = 2\pi \text{rh}$

$⟹2 \times \frac{22}{ \cancel7} \times \cancel{ 0.42} \times 1.2$

$⟹44 \times 0.6 \times 1.2$

$⟹31.68 { \text{cm}}^{2}$

So, Area covered by a roller in 500 revolution

$⟹31.68 \times 500$

$⟹15840 \text{ m}$

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