送交者: steven 于 2005-1-15, 02:46:35:
回答: F is defined as dp/dt. Nothing to do with the real world. 由 008 于 2005-1-14, 16:41:08:
you choose to describe it, the natural phenomena remains the same such that a heavier object fells the same way as a lighter object if air resistence is not present. That is the nature, and that cannot change that.