Puzzler

[ivyfic]

Here's another brain teaser for you (provided by my brother):

You are standing in a boat in a lake holding a rock. You throw the rock into the lake.

What happens to the level of water in the lake?

Again, assume all basic Physics 101 assumptions (no wind, no current, etc.).

Comments

[gryphonrose.livejournal.com]

I'm confused--if the rock displaces less water after being thrown in, wouldn't the water level go up, not down?

[ivy03.livejournal.com]

The more water that is displaced, the higher the water level is. So, since the rock displaces less water when it is in the lake than when it is in the boat, the water level goes down after you throw it.

[gryphonrose.livejournal.com]

Ah yeah, I was having a brain spasm. Duh. Never mind. :)