The diameter and length of a roller are 84cm and 120 cm respectively in how many revolution can the roller level the playground of area 1584 Sq meter
408
So in one rotation, the rollers covers
84π*120 cm^2
number of rotations = 1,5840,000 cm^2/(84π*120) cm^2
= 500.2
How did you get 408?
To determine the number of revolutions required by the roller to level the playground, we need to find the total distance covered by the roller and divide it by the circumference of the roller.
First, let's find the circumference of the roller using the formula:
Circumference = π * diameter
Given that the diameter is 84 cm, we can calculate the circumference as follows:
Circumference = π * 84 cm
Since we know that the value of π is approximately 3.14, we can substitute this value to find the circumference:
Circumference = 3.14 * 84 cm
Circumference = 263.76 cm
Now that we have the circumference of the roller, we can calculate the total distance that the roller covers in one revolution. Since the roller's circumference is equal to the distance traveled in one revolution, the total distance covered is also 263.76 cm.
Next, we need to calculate the area of the playground. Given that the area is 1584 square meters, we know that the roller needs to cover this entire area.
To convert the area from square meters to square centimeters, we need to multiply it by 10,000:
Area = 1584 * 10,000 sq cm
Area = 15,840,000 sq cm
Finally, to find the number of revolutions required, we divide the total distance covered by the circumference of the roller:
Number of revolutions = Total distance covered / Circumference
Number of revolutions = 15,840,000 sq cm / 263.76 cm
Number of revolutions ≈ 60,000 revolutions
Therefore, the roller needs to make approximately 60,000 revolutions to level the playground of an area equal to 1584 square meters.