## Balls puzzle.

You have 2 balls. Both are identical in size and mass, but one is made of gold and is hollow,the other is not hollow and made from titanium. Find out which is which ball, and lets say both are covered with a black paint that is anti reflective, heat/electricity insulator. You can't use any measurement device, nor hitting, damaging or breaking the ball..

P.S: There's a really simple way.
 Knock them? One will sound hollow?
 Mmm.. lets say the paint is anti-acoustics.

Mentor

## Balls puzzle.

Spoiler
Roll the balls side-by-side down a ramp. The solid ball will roll faster.
 wheew.. you're fast..

 Quote by Sakha wheew.. you're fast..
Around here, we like our women that way.
 drop them in water. the hollow one will bob higher. oh..same mass, never mind

 Quote by regor60 drop them in water. the hollow one will bob higher. oh..same mass, never mind
Nice try.
 Recognitions: Gold Member Homework Help Science Advisor Remove the paint? (This as an alternative to lisab's suggestion)
 oohh rigid bodies thats realy good
 put them in a bucket of water they vary in density the gold will pull out more water am i correct?

 Quote by arildno Remove the paint? (This as an alternative to lisab's suggestion)
As I said, you can't damage nor break the ball, and removing the paint would be considered damaging. But yeah, lisab's answer is right.
 Quote by some_one put them in a bucket of water they vary in density the gold will pull out more water am i correct?
Both would pull same amount of water because both are same size and mass, so they have same volume and density.
 Recognitions: Gold Member Homework Help Science Advisor I think black is a damaging colour, I'm merely prettifying the balls..
 aaahhh disregard it you sayed that the gold ball is hollow
 No, imagine a gold sphere as an "o" the black line is gold and the white is hollow... The titanium sphere is all solid.
 if you shoot them out of a cannon the gold ball will not fly in a steady trajectory because its hollow in order to fly in a steady way you need to have a full ball because from my knowledge the AK bullets have a shifted center of mass which make them highly unstable and when they hit a person instead of going forward they are starting to swirl inside the victim am i correct?
 Recognitions: Gold Member Homework Help Science Advisor The middle of the gold ball is empty, some one, it is hollow. The hollowed gold ball can perfectly well have the same size and mass as the compact titanium ball