# Red Hot and loving it

PBE6
Posers and Puzzles 16 Mar '05 20:08
1. PBE6
Bananarama
16 Mar '05 20:081 edit
It seems that most problems presented on this forum are mathematical in nature, with word problems/lateral thinking problems coming in a close second, and chess problems bringing up the rear, funny enough. How about a physics problem or two?

1. Monkey + pulley: A cheeky little monkey is hanging onto a rope that is attached to a pulley, and counter balanced on the other end with a monkey-shaped weight. Both the monkey and the weight are at the same height initially. What happens if the monkey starts climbing the rope?

2. Revolving sprinkler: Everyone has seen revolving sprinklers that spin when the water comes out. Imagine one with two L-shaped arms on opposite sides of the central hub, both pointing clockwise (as viewed from above). When you turns on the water, it spins counterclockwise. What happens if you put this sprinkler under water, and THEN turn it on? Which way will it spin? (BTW, Richard Feynman once wrecked a physics lab trying to answer this question experimentally.)

Bonus points for anyone that can link to video footage of an experiment demonstrating your answer! But you'd better be in the video, or else...
2. 16 Mar '05 21:184 edits
1) By conservation of angular momentum, the weight should stay at the same height as the monkey.

2) Didn't Feynman address the question of what happens when you submerge a sprinkler that sucks water in?

3) Why does a mirror appear to invert the left-right directions, but not up-down?

3. PBE6
Bananarama
16 Mar '05 21:27
Originally posted by THUDandBLUNDER
1) By conservation of angular momentum, the weight should stay at the same height as the monkey.

2) Didn't Feynman address the question of what happens when you submerge a sprinkler that sucks water in?

Oops, I think you're right about question #2. Let's rephrase it your way.

And the answer to question #1 sounds right to me. Can someone please kidnap a monkey and make this video thing HAPPEN?!?
4. Acolyte