PHY152H1 Chapter 18: Field and Forces
Document Summary
Newton"s universal law of gravitation: every single point mass attracts every other point mass with a force that is directly proportional to the product of their masses + inversely proportional to the square of their separation. Sphere"s of mass separation- separation between their centres centre of mass= centre of regularly-shaped bodies. Newton"s 2nd law: f=ma acceleration of free fall on earth= 9. 81ms-2 (average for the whole earth- not entirely circular) Earth"s orbit around the sun elliptical orbit, but taken to be circular for easier calculations centripetal force: circumference=2 r. Gravitational eld: region of space where a mass experiences a force because of its mass. Gravitational eld strength: force per unit mass experienced by a small test mass placed in a eld we are measuring) Field lines measured in nkg^-1 (*big test mass might change the eld drawn in the direction a mass would accelerate if placed in the eld.
