Astronomy 1021 Lecture Notes - Lecture 11: Kinetic Energy, Tidal Locking, Tidal Acceleration

• School: Western University
• Department: Astronomy
• Course: Astronomy 1021
• Professor: Robert Cockcroft

Document Summary

Force, f = ma: previously looked at force, now focus on momentum: Heavy truck moving quickly has large momentum. Small ping pong ball moving slowly had small momentum. Momentum & force: the o(cid:374)ly way to (cid:272)ha(cid:374)ge a(cid:374) o(cid:271)je(cid:272)t"s (cid:373)o(cid:373)e(cid:374)tu(cid:373) is to apply a fo(cid:396)(cid:272)e to it, this is the sa(cid:373)e as newto(cid:374)"s 2nd law (f = ma) Conservation of momentum: the total momentum of interacting objects cannot change as long as there is no external force acting on them, or total momentum is conserved. Objects bounce off one another: inelastic: ke is not conserved. Rotating object: no overall velocity, therefore no overall momentum: however, all parts are rotating, so these parts have momentum, the further away from the rotation axis a part is, the larger its speed (and thus momentum) Angular momentum: angular momentum is adding up the momentum of all the parts for a spinning or orbiting object.