Okay, so here's the set-up - if you take two beakers of water and submerge a ping pong ball in one, and a heavier, acrylic ball in the other, which one will weigh more? This challenge, posed in Veritasium's latest episode, seems like it should be easy, but the physics going on behind the scenes is pretty fascinating.
Before you make your prediction, it's important to note that both balls are identical in size and shape, but the lighter one is tied to the bottom of the beaker to keep it submerged at half-way, and the heavier one is kept at the same spot by a thread from above.
If you're like me, you'll think that the beaker containing the heavier ball will sink. It should be simple, right? Then again, both balls are displacing the same amount of water, so maybe they'll stay balanced? But, as usual, nothing's as easy as it seems when it comes to physics, and there are a whole lot of other forces at play here.
We don't want to give too much away, because Veritasium does such a great job of explaining it in his solution video. But we will give you a little hint: you should be thinking about not just how much water is being displaced, but also the amount of force on that water.
Watch above and test your physics skills.