Question

The height of a tree trunk is 20 meters and the base diameter is 0.5 meter.

Answer 1

Question a:

Mass = Density × Volume 
Density = Mass/Volume

Volume of the tree trunk (the shape of Cylinder) = Area of circular base × height
Volume = [πr²] × h
Volume = [π × 0.25²] × 20
Volume = 3.93 m³

Density = 380 kg/m³

Mass = Density × Volume
Mass = 380 × 3.93
Mass = 1493.4 kg

------------------------------------------------------------------------------------------------------------

Question b)

The growth ring = 4 millimeters = 4÷1000 = 0.004
New diameter = 0.5 + 0.004 = 0.5004
New height = 20 + 0.2 = 20.2

New volume = [πr²] × h
New volume = [π × 0.2502²] × 20.2
New volume = 3.97 m³