Force needed to draw a cart up a slope
A rule proving that gravity is halved along an oblique line
This page sets out a rule for finding the force required to draw a cart up a mountain or along any oblique line. A diagram inscribes a square and an inclined line within a circle, with the loaded cart-wheel at the centre and the labelled points a, n, o. Leonardo argues that when the weight's centre falls at the midpoint of the oblique line, the gravity felt by the mover is halved, so a 2000-pound load registers as only 1000 pounds.
On this page
Rule for the force to haul a cart up a slope
The page opens with a rule for determining what force is needed to pull a cart up a mountain or along any oblique (inclined) line. It frames the problem of hauling a load along a slanting path rather than along level ground.
Weight halved on the oblique line at point n
A 2000-pound load is drawn along an inclined 'line of motion', yet the mover feels only 1000 pounds. Because the weight's centre m rests on the oblique line at a, and the perpendicular of gravity falls at the midpoint n of the line a o, the effective weight on the mover is reduced by half.