Note:
Use Q1 and Q3-6 from GCSE volumes of 3D shapes (remodel Q4 and Q6)
Volumes of 3D Shapes FSQ2
Dylan runs a steel manufacturing company producing parts for other businesses.
One of his products is a small, circular disc.
His website lists the product with the following diagram:
Using the diagram, calculate the volume of the disc.
You should use a value of \pi = 3.14
Give your answer to 2 decimal places.
Answer: 32.97 mm^3
Workings:
The volume of the disc can be calculated by first working out the area of the cross-section, i.e. the hollow circle:
Area of larger circle = \pi r^2 = 3.14\times4^2=50.24 mm^2
Area of smaller circle (cut-out section) = \pi r^2 = 3.14\times3^2=28.26 mm^2
Area of cross section =50.24-28.26=21.98 mm^2
So the volume can be calculated as:
Volume =21.98\times1.5=32.97 mm^3
4 marks