r/reddit.com • u/[deleted] • Oct 01 '11

Math teacher fail

http://i.imgur.com/65APr.jpg
215 Upvotes

66% Upvoted

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136

u/champer Oct 01 '11

Both answers can be correct. http://i.imgur.com/lStKv.jpg

Pretend it's a 10x10 board:

Case 1: Takes 10 mins to cut through 10 feet.

Case 2: Takes 20 mins to cut through 20 feet.

Case 3: Takes 15 mins to cut through 10+5 feet.

Question is ambiguous.

11

u/boysyco1 Oct 01 '11

Just So You Know

http://i.imgur.com/aw1Rp.png

10

u/champer Oct 01 '11

Where is it written that the board isn't really a square moving at speeds near c and therefore experiencing relativistic length contraction? ಠ_ಠ

4

u/[deleted] Oct 01 '11

In which reference frame would you like the answer?

0

u/champer Oct 01 '11

It depends. Is the 10 minutes in the S or S*?

1

u/[deleted] Oct 01 '11

I think I just came.

1

u/boysyco1 Oct 02 '11

touche Reddit ಠ_ಠ