Video Transcript
Work out the volume of the sphere,
giving your answer accurate to two decimal places.
In this example, we’re given a
sphere with diameter 7.6 centimeters. And we want to find the volume of
that sphere.
First of all, we know that the
radius is half the diameter. So the radius of this sphere is 3.8
centimeters. That’s one-half of 7.6. Now we know that the volume of a
sphere of radius 𝑟 is given by four over three 𝜋𝑟 cubed. And substituting our value of 𝑟
equals 3.8 into this, we have the volume of the sphere is equal to four over three
𝜋 times 3.8 cubed.
Taking 𝜋 equal to 3.14159 and so
on and 3.8 cubed equals 54.872, we have 𝑉 equal to four over three times 3.14159
times 54.872. This evaluates to 229.84729 and so
on, which, to two decimal places, is 229.85. Since we’re working in centimeters,
the volume of the given sphere with diameter 7.6 centimeters is 229.85 cubic
centimeters to two decimal places.
