Question

Find the radius of an aluminum cylinder that is 2.00 cm long and has a mass of 12.4 g.
V = pi* r^2 * l

Answer 1

your answer will be to your question will be: the radius is 4m

Answer 2

Aluminium cylinder:  m = 12.4 g,  L = 2.00 cm.
V = π r² L
Density of the aluminium: 2.7 g / cm³
V = 12.4 g : 2.7 g/cm³ ≈ 5 cm³
5 = 3.14 · r² · 2
r² = 5 : 6.28
r² = 0.796
r = √0.796
r = 0.9 cm
Answer:
The radius of an aluminium cylinder is 0.9 cm.