Lecture 3 Flashcards Preview

AST205 > Lecture 3 > Flashcards

Flashcards in Lecture 3 Deck (33)
Loading flashcards...
1
Q

Which planets have rings?

A

Jupiter, Saturn, Uranus, Neptune

2
Q

How are rings formed?

A

Tidal forces of a planet stretch objects that come in too close and break them apart

3
Q

What is the Roche-Limit of a moon?

A

The point at which the moon will break apart in tidal forces

4
Q

What is energy?

A

The ability of an object to do work, a scalar

5
Q

What is work?

A

Force acting over a distance (Work = F*d)

6
Q

What is power?

A

Energy / unit time

7
Q

What is the equation for Kinetic Energy?

A

E=1/2mv^2

8
Q

How is energy stored?

A

It is stored as potential energy whenever a force moves a particle through a field that the particle interacts with.

9
Q

What is the equation for potential energy?

A

E=mgh

10
Q

When does a cloud in space have more gravitational potential energy?

A

When it is very spread out.

11
Q

In what kind of system is energy conserved?

A

In an isolated system

12
Q

What does Noether’s theorem state?

A

The laws of physics do not change over time (time invariance)

13
Q

When is a spring more massive?

A

After you compress it because of the energy you put in

14
Q

What kind of energy is light?

A

Radiative energy

15
Q

What factor determines the intensity of light?

A

The amplitude of the photon

16
Q

What factor determines the color of light?

A

The energy of the photon

17
Q

What does a diffraction grating do?

A

Produces the same effect as a prism (e.g. on the bottom of a CD)

18
Q

WHat are the four ways in which matter can react?

A

Transmission, absorption, emission, and reflection

19
Q

What kinds of objects transmit light?

A

Transparent objects

20
Q

What kinds of objects Emit light?

A

Example: lightbulb

21
Q

What kinds of objects absorb light?

A

opaque objects

22
Q

What kinds of objects reflect light?

A

Mirrors

23
Q

What is a wave?

A

A disturbance / oscillation that travels through spacetime with no mass transfer but some energy transfer.

24
Q

What is unique about cherenkov radiation?

A

That particles move faster in water than light does in water.

25
Q

What is millimeter astronomy?

A

Astronomy based on lights of wavelengths of 1 to 3 millimeters

26
Q

What is submillimeter astronomy?

A

Astronomy based on lights of wavelengths less than a millimeter long.

27
Q

How can we predict what objects are composed of using light?

A

Light interacts in different ways with different objects. Thus by recording the light that comes through / bounces off an object, we can predict the substances that caused the light to do that.

28
Q

What kind of charges produce an electric field?

A

Stationary charges

29
Q

What kind of charges produce a magnetic field?

A

Moving charges

30
Q

What do Maxwell’s equations describe?

A

The properties and interactions of electric and magnetic fields.

31
Q

What was the effect of Young’s double-slit experiment?

A

Observed the wave-particle duality

32
Q

On what does the photoelectric effect depend?

A

On frequency ALONE

33
Q

What was Roemer’s experiment?

A

He used the eclipses of Io, Jupiter’s moon to calculate the speed of light, but was off due to inaccurate measurements.