Hello! If I pedal a bicycle, where is the force that moves the bike forward horizontally applied? Is it the bottom of the back wheel or the center of the back wheel? When the force applied to that point is F, does all that force goes into horizontal acceleration, or does some of that force go vertically agaisnt gravity, because there is an angle between the horizontal force and the center of mass? Would the actual horizontal force then be F*cos(a) ? If anyone could help I would be thankful.