Class Notes (838,386)
Canada (510,872)
Physics (324)
PHYS 183 (78)
Tracy Webb (34)
Lecture 9

Lecture 9

2 Pages
97 Views
Unlock Document

Department
Physics
Course
PHYS 183
Professor
Tracy Webb
Semester
Winter

Description
PHYS 183 – The Milky Way Inside and Out – Tracy Webb Winter 2013 th Lecture 9: January 25 , 2013  a law is a description of the way the universe behaves  the universal laws of gravitation o every mass attracts every other mass  the earth is attracting you to the earth, but you are also attracting the earth o the strength of attraction is directly proportional to the product of their masses  if you double the mass of something, the force of gravity is doubled too o the strength of attraction is inversely proportional to the square of their separation distance  if distance goes up, the force of gravity goes down (not linear) 2 o Fg= G (M1M 2d ) o force of gravity = gravitational constant (mass of object 1 x mass of object 2 / distance between the two objects squared)  usually rare a scientific theory is completely wrong  as we gain new knowledge we usually change - the theories, not start from scratch  centre of mass o objects orbit around their centre of mass o for 2 objects of equal mass, centre of mass lies halfway between them o for 2 objects of different masses, centre of mass lies closer to the more massive one o if 1 object is so much more massive that the planet, the centre of mass can lie inside the star o important for extra solar planets  Newton and Kepler’s Third Law o Kepler found P = a for our solar system (P in years, a in AU) o Newton showed that this is a special case of the general behaviour of orbits o using the orbital period and orbital distance we can now find the total mass of a system  measuring masses o for the special case of one dominant mass (and a small satellite) o the earth’s orbital period (1 year) and its distance from the sun (1 AU) tells us the mass of the sun o the orbital period & distance of a satellite orbiting the earth tells us the earth’s mass o the orbital period and distance from Jupiter of one of Jupiter’s moons tells us the mass of Jupiter  orbits, tides and acceleration
More Less

Related notes for PHYS 183

Log In


OR

Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


OR

By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.


Submit