A shot – put made of iron

Volume of sphere = $ \frac{4}{3}\pi r^3 $
Diameter of sphere = $ 12 \text{ cm} r = 6 \text{ cm} $
Volume of sphere = $ \frac{4}{3}\pi (6)^3 = \frac{4}{3}\pi \times 216 = 288\pi \text{ cm}^3 $
Volume of cylinder = $ \pi R^2 h $
Height of cylinder h = $ 2 \text{ cm} $
Since volume is conserved:
$ \pi R^2 \times 2 = 288\pi $
$ 2R^2 = 288 $
$ R^2 = 144 $
R = 12 cm
Diameter of cylinder = 2R = 24cm
Answer = 24 cm