View Single Post
Old 2009-03-31, 11:06   #1
Andi47
 
Andi47's Avatar
 
Oct 2004
Austria

2·17·73 Posts
Default How fast is the dog?

A dog decides to run 500 km. It has got an empty cane tied on its tail, which hits the ground exactly once every second with a loud "clonk!" sound.

The dog starts its run with the first clonk it hears, with a velocity of 2 m/s. Afterwards it doubles its velocity instantly (i.e. with infinite acceleration) every time when it hears a clonk from the cane.

How fast is the dog when it reaches its destination?
Andi47 is offline   Reply With Quote