Want to know how to work out the volume of a sphere? Just read on!
A perfectly round three dimensional shape with all points on its surface equal distance from its center.
Examples include balls used in sports such as ping pong, soccer and tennis.
The amount of three dimensional space occupied by the sphere.
where
The radius of a sphere is the distance between its center and any point on its surface.
Work out the volume of a ping pong ball with radius (r) 2cm (centimeters).
Vsphere
= 4/3 x πr³
= 4/3 x π x 2³
= 33.5cm³ (cubic centimeters) to 1 d.p. (one decimal place)
You can use the xy button on your calculator to work out 2³. You may need to press a shift or 2nd function button to access π and xy. The key sequence for the above calculation is 4, divide sign (÷), 3, multiply sign (x), pi sign (π), 2, xy, 3, equals sign (=). Your calculator should display 33.51032164 which is 33.5 to 1 d.p.
Vsphere
= 4/3 x πr³
= 4/3 x π x 11³
= 5575.3cm³ to 1 d.p.
On your calculator, press 4, divide sign (÷), 3, multiply sign (x), pi sign (π), multiply sign (x), 11, xy, 3, equals sign (=).
Vsphere
= 4/3 x πr³
= 4/3 x π x 3.4³
= 164.6cm³ to 1 d.p.
The calculator key sequence remains the same as for the ping pong and soccer ball calculations except enter 3.4 for the radius (r).
Think of some other examples of spheres and use their different size radiuses to calculate their volumes.
How about the following? Remember Vsphere = 4/3 x πr³
Spherical object |
Radius (r) |
Volume (Vsphere) |
Baseball |
3.7cm |
212.2cm³ to 1 d.p. |
Basketball |
12cm |
7238.2cm³ to 1 d.p. |
Beach volleyball |
21cm |
38792.4cm³ to 1 d.p. |
Enjoyed learning about the volume of a sphere? Next up - the surface area of a sphere.
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