Originally Posted by
mike_s
So, if I find a Ferrari on sale for $400,000 instead of $500,000, I'll be $100,000 richer if I buy it!
It's all BS.
Make a wheel with 4 spokes distributed evenly across 1/2 the circumference. Now see how much weight that wheel supports when the spokes are 1) on the top, 2) on the bottom.
Now build a wheel using fishing line for "spokes." Try and tell people that it's supported by the "spokes" at the bottom.
It should be perfectly clear to anyone with any common sense that the weight is supported by spokes in tension. Adding weight increases that tension. Anyone arguing that the spokes on the bottom somehow support that weight is playing fast and loose with terminology to make some nonsensical point.
Depends on how much the Ferrari is worth whether you are richer or poorer and by how much. For example, if you find yourself a really nice old Schwinn Paramount for $100 and buy it, you are probably richer as a result of the bargain.
It's not correct to say that the load is supported by spokes which see an increase in tension. What is correct is that when a load is added to the hub it is supported by the net change in tension of all the spokes. It turns out that the sum of the changes in all the vertical components of tension in all the spokes will equal the weight added to the hub. If it did not, the hub would accelerate.
Another way that you can look at this that might help is to consider that tension in the spokes has a direction up and down. That is, tension can be either a positive or a negative quantity. If you look at the change in tension of the various spokes without accounting for direction you will say that the bottom spokes decrease in tension while the upper spokes increase in tension. But, if you account for the fact that tension has a direction and if you call the up direction the positive direction, you will conclude that the tension in the bottom spokes increases too. The tension in the bottom spokes becomes less negative when the load is applied; that is, it increases.