Lecture 9

Describes the way the frequency of a wave appears to change if there is relative motion between the wave source and the observer

When they are stretched they have a lower frequnecy and lower pitch, when they are bunched they have a higher frequency and higher pitch.

The higher the frequency of light it will be blueshifted and look bluer as it moves towards you. It will be red shifted and look red as it moves away from you lowering the frequency.

It allows you to study shifts due to stellar wobble and is what the big bang theory is based on

The Ptolemy (2nd C AD) earth at the center circular orbit model, and the Copernicus (1543) sun at the center circular orbit model

Tycho Brahe in the 16th century invented the azimuthal quadrant and pointed it towards Mars, taking detailed measurements of its movements.

He was a mathematician who looked at his boss Brahe’s work after he died and found that neither og model was correct

All planets, including Earth, orbit the sun in elliptical, not circular orbits. Where Da (planet-sun) +Db (planet-focus point 2) = constant

He is the father of mechanics: motions of material objects, who found the sunspots on the sun, and Jupiter’s 7 moons

Speed and velocity create uniform motion where an object travels in a straight line at a constant speed or at rest. Acceleration = every other motion that involed a change in speed or direction or both

Velocity describes motion with both a direction and magnitude; it is a speed in a given direction. Speed has no direction only magnitude, it is how fast you are traveling

velocity = distance/time where velocity is speed with direction

Acceleration in m/s squared= (velocity final - velocity initial)/ time

Mathematical laws in falling objects, using relationships between distance, time, velocity, and acceleration. Objects accelerate while falling, and all objects on Earth’s surface accelerate at the same time. And to describe falling objects, you need to measure distance and time

He sent balls down an inclined plane and measured the time of descent by listening to the “ping.” The balls accelerated moving down the plane and increasing the angle increased the acceleration

Velocity was curbed when put on a graph meaning it was not constant and was changing meaning it was accelerating

proportional to the time of it’s fall. Meaning a rolling ball increased in velocity at a constant rate as when it starts from rest the velcoty is proportional to the length of time it has been falling. Velocity = (a - constant depends on the angle unless the angle is 90 degrees) x (time)

Acceleration when an object is falling freely =g on Earth only. g=9/8 m/s^2, which is the constant acceleration of all objects that fall as the strength of gravity is proportional to the mass of the objects involved. It will travel a distance of 1/2at^2

Mass is the amount of matter in an object, and weight is the force of gravity pulling on an object

velocity = g x times. The velocity keeps increasing over time, causing the object to accelerate, as the longer you go, the faster you fall at the constant acceleration of 9.8 m/s^2

He pushed Galilei’s stuff further and demonstated the universaility of the forces of gravity and asked what causes object to move