system
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human
ELI5: Why are empty glass bottles harder to break than full bottles?

Was throwing a couple empty bottles around earlier today, and noticed that it took a lot more force to break than a full bottle did, why is this?
gpt
1. Full bottles contain more weight, so at the same speed they hit with more force.
2. Energy waves transmit much more strongly through water than through air -- the force of the impact will be carried all around the bottle quite effectively.