More specifically: could a 2-litre milk carton like the one pictured below be used to knock someone unconscious via a single blow to the head, or would the carton burst from the force?
Here is some information I could find on the carton and the milk:
The rectangular base is approximately 9.5cm x 9.5cm, and the rectangular prism portion of the carton is 21cm tall. The total height of the carton is approximately 25.5cm tall. The milk fills the entire rectangular prism but not the rest of the carton. The total volume of milk is approximately 9.5cm x 9.5cm x 21cm or 1895.25cm-cubed. That gives an approximate volume of 1.89525 litres of milk and an approximate mass of 1.9521075 kg of milk (the density of milk is approximately 1.03 kilograms per litre).
I've thought about asking this on physics.SE or biology.SE but I don't know if it would be considered on-topic.
If this question would be better suited somewhere else, please migrate it.