These last weeks many of us have been following the olympics.
I was watching the canoe races and was impressed by the skill and energy of athletes.
I thought if an olympian would have several boomerangs and the skills to be able to throw them in a way that he can get them back. If he repeats this throwing in a regular pace say once per second, could he get propulsion out of this chain of action like a rocket engine and make the canoe move? Assuming he is skillful enough to throw them in a way that they burn most of their energy in the air as drag?
Example and some numbers
So he ejects them with high speed and retrieve them with low speed?
lets say an efficient boomerang thrower uses 1 kilogram boomerangs and throw them at a speed of 36 kilometers/hour at a rate of one per second. So he is exerting $ E=1/2 (1.(9.8)*(36*1000/3600)^2= 500 watts $ which is beyond our dream but Olympians may be able to do it.
If he can make them come back and land gently on the basket he has for them he can produce o.7 horse power! It would be an exciting game to watch.