/sci/ - Science & Math

>>>/n/1452207
>the energy stays proportional to the mass without affecting the speed. we can ignore friction when only comparing the weight assuming the bikes have similar aero and the rolling resistance of the heavier bike could be adjusted accordingly by giving it a higher tire pressure.

>>>/n/1452225
>Two marbles with different weight but equal diameter will roll down a hill equally fast in a vacuum.
>On earth, the heavier marble will be faster because it has more potential energy stored to overcome the aero drag. The aero drag increases with a cubed correlation to speed so it is very significant.

who's right

also how does buoyancy relate to all of this?