To find the volume of a sphere, use the formula:
V=43πr3V=\frac{4}{3}\pi r^3V=34πr3
where VVV is the volume and rrr is the radius of the sphere. The radius is half the diameter, so if you know the diameter ddd, then r=d2r=\frac{d}{2}r=2d.
Steps to calculate the volume:
- Determine the radius rrr of the sphere (half the diameter if only diameter is known).
- Cube the radius: r3r^3r3.
- Multiply by π\pi π (approximately 3.1416).
- Multiply by 43\frac{4}{3}34.
Example:
If the diameter is 14 cm, then the radius r=7r=7r=7 cm.
V=43π(7)3=43×π×343≈1436.8 cm3V=\frac{4}{3}\pi (7)^3=\frac{4}{3}\times \pi \times 343\approx 1436.8\text{ cm}^3V=34π(7)3=34×π×343≈1436.8 cm3
This gives the volume in cubic centimeters
Alternative formula using diameter:
You can also use the formula directly in terms of diameter:
V=πd36V=\frac{\pi d^3}{6}V=6πd3
which comes from substituting r=d2r=\frac{d}{2}r=2d into the volume formula
. This method allows you to calculate the volume easily if you know either the radius or the diameter of the sphere.