AST101H1 Lecture Notes - Lecture 7: Cruise Control

• School: UTSG
• Department: Astronomy & Astrophysics
• Course: AST101H1
• Professor: Bryan Gaensler

Document Summary

Clicker q&a: a car is travelling due north at 100km/hr. Clicker q&a: a(cid:272)(cid:272)ordi(cid:374)g to newto(cid:374)"s laws a (cid:271)all o(cid:374) a flat surfa(cid:272)e rolls to a stop. A force (known as friction) acts on the ball which causes it to stop. Clicker q&a: a(cid:272)(cid:272)ordi(cid:374)g to newto(cid:374)"s laws a(cid:374) astro(cid:374)aut pushes herself away from her large spacecraft. She and the spacecraft moves apart- she moves faster than the spacecraft: momentum: mass times velocity, p=mv. It is always the same since angular momentum is conserved. If one doubles the mass of either object, you double the force. If one halves the mass of either object, you half the force: force depends on distance between the center of mass of 2 objects. If you double distance, you reduce force by a factor of 2x2=4. If you half distance, you increase force by factor of 2x2=4: farther away = less force; closer = more force. When the comet is closest to the sun.