ok, im studying mech2 in maths atm, im still only doing gcse physics, so i havnt covered anything thats contained in mech2 in physics yet, but theres something thats confusing me

im creating a physics engine in c++, and im ready to add in some rigid body spheres to the enviroment, in terms of rigid body physics, its pretty simple, since any force, will not induce any rotation, however to make it look more realistic, when moving on the ground i want it to actually physicall roll aswell, so i took my knowledge from rigid body physics to induce rotation via the friction with the ground, and it worked perfectly.

but this got me thinking, how exactly in cars etc, does the rotation itself cause movement via friction?

from my mechanics in maths, ive learnt that friction is F = uR where R is the normal contact force, but simple rotation on its own of a circle/sphere doesn't alter the normal contact force, so i cant quite understand how it causes it to increase so as to move the circle/sphere.

the only thing i can think to explain it, is that in real life, theres always going to be some level of deformation which alters the perfect state of the body, and such would cause the normal contact force to be altered and induce more friction in rotation.

Last edited by luca-deltodesco (2007-04-03 18:52:31)