The volume of the cylinder is related to the capacity of that geometric figure. Remember that the cylinder or circular cylinder is an elongated and rounded geometric solid.
It has the same diameter along the entire length and two bases: upper and lower. The bases are two parallel circles with equal radii.
The radius of the cylinder is the distance between the center of the figure and the end. Thus, the diameter is twice the radius (d = 2r).
Many cylindrical figures are present in our daily lives, for example: batteries, glasses, cans of soda, chocolate, peas, corn, etc.
It is important to note that the prism and the cylinder are similar geometric solids, and their volume is calculated using the same formula.
Formula: How to Calculate?
The formula for finding the volume of the cylinder corresponds to the product of the area of its base by measuring the height.
The volume of the cylinder is calculated in cm 3 or m 3 :
V = A b .h or V = π.r 2 .h
Where:
V : volume
A b : base area
π (Pi): 3.14
r : radius
h : height
Solved Exercises
1 . Calculate the volume of a cylinder whose height measures 10 cm and the diameter of the base measures 6.2 cm. Use the value of 3.14 for π.
First, let’s find the radius value for this figure. Remember that the radius is twice the diameter. For this, we divide the diameter value by 2:
6.2: 2 = 3.1
Soon,
r: 3.1 cm
h: 10 cm
V = π.r 2 .h
V = π. (3.1) 2 . 10
V = π. 9.61. 10
V = π. 96.1
V = 3.14. 96.1
V = 301.7 cm 3
2 . A cylindrical drum has a base of 60 cm in diameter and a height of 100 cm. Calculate the capacity of that drum. Use the value of 3.14 for π.
First, let’s find the radius of this figure, dividing the diameter value by 2:
60: 2 = 30 cm
So, just put the values in the formula:
V = π.r 2 .h
V = π. (30) 2 . 100
V = π. 900. 100
V = 90,000 π
V = 282,600 cm 3
Vestibular Exercises with Feedback
The theme of cylinder volume is widely explored in the entrance exams. Therefore, check below two exercises that fell in the ENEM:
1 . The figure below shows a water tank in the form of a straight circular cylinder, 6 m high. When it is completely full, the reservoir is enough to supply, for a day, 900 houses whose average daily consumption is 500 liters of water. Suppose that, one day, after a water use awareness campaign, the residents of the 900 houses supplied by this reservoir have saved 10% in water consumption. In this situation:
a) the amount of water saved was 4.5 m 3 .
b) the height of the water level left in the reservoir, at the end of the day, was equal to 60 cm.
c) the amount of water saved would be enough to supply a maximum of 90 houses whose daily consumption was 450 liters.
d) the residents of these houses would save more than R $ 200.00, if the cost of 1 m 3 of water for the consumer was equal to R $ 2.50.
e) a reservoir of the same shape and height, but with a base radius 10% smaller than the one represented, would have enough water to supply all the houses.
Answer
Answer: letter b
2 . (Enem / 99) A cylindrical bottle is closed, containing a liquid that almost completely occupies your body, as shown in the figure. Suppose that to make measurements, you only have a millimeter ruler.
To calculate the volume of the liquid contained in the bottle, the minimum number of measurements to be performed is:
a) 1
b) 2
c) 3
d) 4
e) 5
Answer:
Answer: letter c