Textbook Notes (363,260)
Canada (158,278)
Astronomy (66)
AST201H5 (14)
J B Lester (10)
Chapter 4


2 Pages
Unlock Document

University of Toronto Mississauga
J B Lester

AST 201S - Stars and Galaxies University of Toronto Mississauga Chapter 4 Summary th Essential Cosmic Evolution, 5 Edition 1. Precise definitions of terms relating to motion: • speed = change of location/position in an amount of time - m/s • velocity = change of location/position in a particular direction in an amount of time - m/s • acceleration = change in velocity in an amount of time - m/s/s or m/s 2 • momentum = mass × velocity - has direction • net force = sum of all force affecting an object 2. Mass = amount of matter in a body 3. Weight = force of gravity on the mass of an object 4. Newton’s laws of motion. (a) 1 Law: If there is no net force, the momentum remains constant - same speed and same direction (b) 2nd Law: If there is a net force, the momentum changes - either the speed changes or the direction changes or both the speed and direction change rd (c) 3 Law: For every force there is an equal and opposite reaction force 5. Newton’s law of gravity (a) F g G M1×2 2 d (b) Note: F gepends directly on both masses multiplied together (c) Note: F gepends inversely on separation squared (d) Because mass is always positive, there is never a cancellation, as can happen with + and − electric charges or N and S magnetic poles (e) As the separation increases the force of gravity weakens, but never goes to zero if the separation is less than infinity (f) Gravity is extremely
More Less

Related notes for AST201H5

Log In


Don't have an account?

Join OneClass

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

Sign up

Join to view


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.