Quote:
Originally Posted by OneOfOne
I don't know if I agree with their answer, I consider it to be the LEAST correct. The jugglers static weight for most of the time will be 47+2kg. At any instant he will need to provide energy to accelerate a single pin into the air, which will temporarily increase his "weight" to something above the static 49kg, this amount being dependent on the height to which he throws the pin, the higher it goes, the more the force, the greater the increase in his weight. Once the pin has been released, his weight will drop to 47kg as all pins will be in the air and so will have no influence on his weight. At some instant, he will need to catch a single pin and his effective weight will increase again, probably by the same amount it increased when he threw the pin into the air. So his maximum weight will average to something around 49kg plus the force to accelerate a single pin....
If you pushed the experiment to the limit, he could throw 4 pins high enough into the air that he would not need to catch them until he gets to the other side and would only need to throw a single pin into the air whilst on the bridge...
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The question is what is the total load on the bridge. The total load is the sum of all the gravitational and inertial forces applied to the bridge. In this context the gravitational force is the weight of the juggler and the pins.
The inertial force needs to be greater than 2 kg-force for each pin. The inertial force acts on the bridge irrespective if the pin is about to leave the juggler's hand or is airborne.
The total load on the bridge exceeds 57kg.
Regards
Steven