What is the mass in kilograms? Are you strong enough to lift it?

Question

You wish to defeat Superman for your own nefarious purposes. You have obtained a 4.00 in
diameter sphere of Kyptonite (denisity = 26.7 g/cm3).

Answer 1

To cheat a little, 4 in = 10 cm (appx). Then the volume of the sphere is 8*pi/27 * d^3. Since 8*pi/27 is about 1, the volume is about 1000 cc.
So the mass would be about 26 kg or appx 60 lb.
Liftable, but not too comfortable.