Thank you all, what great responses. I guess this would clarify my confusion (?) a bit: The work expended due to a Force active over a distance is described as W= ∫F°dL. So a force acting on an object over a certain length L is W. It seems that this doesn't apply with the force of Gravity...
Thanks, but my experience is that the heavier rider, Rider A, passes rider B while coasting down hill, even if they start at the same velocity, v0. PHyzguy's analysis indicates the opposite should occur. I believe Newton's 2nd law of motion indicates that in a vacuum (no friction/resistance), a...
Thanks, Wind resistance and friction definitely have an impact, but with me being the larger rider with a presumably larger cross section, I would think I have more wind resistance than the smaller rider. The friction of my bike's bearings and tires on the road, has got to be negligible. I...
How does conservation of energy relate to Gravity? The moon seems to rotate around the Earth for eternity (so it seems). But intuitively I would think that the energy of Gravity would eventually deplete and the moon would drift off into space. This apparently isn't the case. I know that...
So I'm a 195# cyclist, coasting down a hill. I pass the 120 # cyclist who is also coasting. I'm not sure why. Ignoring wind resistance and friction - which I believe aren't significant here - shouldn't we accelerate at the same rate? I believe it has to do with the fact that I'm carrying...