A lawnmower takes 750 complete revolutions to cut grass on a field. Calculate the area of the field if the diameter of the lawnmower is 84 cm and length is 1 m.
Answers
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Given-
length of lawnmower = 1m = 100cm
revolutions= 750
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To Find-
The area of the field
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Solution-
Its circumference
=> π × D = 22/7 × 84
=> 264 cm
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Length of field will be =
=>264 × 750
=> 198000 cm
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Here,
The width of field = length of the lawnmower i.e. 100 cm
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So,
area of field
=> 198000 × 100
=> 19,800,000 cm²
=>1980 m²
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The area of the road in 750 revolutions = 1980 m²
Given :
Diameter of roller = 84
Height of roller = 1 m
To find :
The area of the road in 750 revolutions =?
Step-by-step explanation:
Diameter of roller = 84 [Given]
So, Radius => d/2 => 84/2 = 42 or 0.42 m
And height = 1 m [Given]
In one revolution, the road roller will cover an area equal to its lateral surface area.
Lateral Surface Area of cylinder = one revolution the area of the road covered = 2πrh
Substituting the values in the above formula, we get,
= 2 x 22/7 x 0.42 x 1
= 2.64
So, Area of the road in one revolution = 2.64 m²
Therefore, the area of the road in 750 revolutions = Area of the road in one revolution × 750
= 2.64 x 750
= 1980 m²
Thus, the area of the road in 750 revolutions = 1980 m²