AST 101 Exam 2 Laws of Astrophysics – Flashcards

Planets travel in elliptical orbits with the sun as a focus

The line going from the Sun to the planet sweeps out equal areas in equal times *Explains relationship between planets around the sun

The time that a planet takes to go around the sun increases as the 3/2 power of the long axis of the ellipse T^2=A^3

Applies physical laws discovered on Earth to phenomena in cosmos

An object moves at a constant velocity unless a net force acts to change its speed/direction *In the absence of a net force and object will move with constant velocity

Net force will change an objects momentum, accelerating it in the direction of the force *2nd law states: The amount of acceleration depends on the object's mass and the strength of the net force Force= mass x acceleration "F=ma"

ANGULAR MOMENTUM- Special type of momentum that we use to describe objects turning in turning in circles/going around curves

An individual object can change its angular momentum only by transferring some angular momentum to or from another object--> Total angular momentum can never change Angular Momentum= Mass x Velocity x Radius

Every Force is paired with an equal and opposite reaction force *Scenario: Standing on pavement...you are not sinking. No net force acting on you that percisely offsets the downward force you exert on the ground

Any two masses attract each other with a force equal to a constant (constant of gravitation) multiplied by the product of two masses and divided by the square distance between them