Question

A diamater of roller 42cmand length 120cmits take 500revolution level a play ground and find its area

Answer 1

----------------------------------------

Here is the solution:

----------------------------------------

Find the radius:

Radius = Diameter ÷ 2

Radius = 42 ÷ 2 = 21 cm

Find 1 revolution:

I revolution = 2πrh

1 revolution = 2π(21)(120) = 15840 cm²

Find 500 revolutions:

1 revolution = 15,840 cm²

500 revolutions = 12840 x 500 = 7,920,000 cm²

Find in m²:

7,920,000 cm² = 7,920,000 ÷ 100 ÷ 100 = 792 m²

Answer: The area is 792 m²

Answer 2

◻️◽$\bold {\huge {Solutions :-}}$ ◽◻️


$\bold {\underline {We have, }}$

Diameter = 42 m
Length = 120 cm
Revolution = 500


$\bold {\underline {Now, }}$

Radius
= Diameter/2
= 42/2 = 21 cm


1 revolution = 2πrh
= 2π(21)(120)
= 15840 cm²

1 revolution = 15840 cm²
$\bold {\underline {So, }}$
500 revolutions
= 12840 x 500
= 7920000 cm²


Convert into m²

7920000 cm²
= (7920000) /100 × 100
= 7920000/10000
= 792 m²

$\bold {\underline {Hence, }}$
$\bold {The ~area~ is ~792 ~m^2 }$