Newton's law of restitution. Could someone tell me what the easiest form of this law to use is? I usually try to use e=(v(2)-v(1))/(u(1)-u(2)).
Does the law also work if I don't know the direction of v(1) and v(2)?
So for example, if a particle moving with u(1) hits a steady object and I don't know if the particle's speed vector will change its direction, can I still use the law in the form e=(v(2)-v(1))/(u(1)-u(2)) with u(2)=0 (since the object was steady originally)?