Lecture 5

Question 1

First law of thermodynamics

Answer 1

Law of conservation of energy, qgained=qlost

Question 2

Waves are characterized by..

Answer 2

wavelength(gamma), frequency(v) and speed(c)

Question 3

Phase speed is always…

Answer 3

constant

Question 4

Equation for Radiation

Answer 4

E=hv=hc/gamma, h is Plank’s constant 6.63*10^-34

Question 5

What are the wavelengths along the electromagnetic spectrum from smallest to biggest?

Answer 5

x-rays and gamma rays, UV rays, visible light, infared, microwaves and radiowaves

Question 6

What are the wavelengths of the visible light spectrum from smallest to greatest?

Answer 6

Violet, Blue, Green, Yellow, Orange and Red

Question 7

Flux

Answer 7

rate at which energy or mass passes through a unit area

Question 8

Luminosity vs. Brightness

Answer 8

Luminosity is the same for one object. Brightness is dependent on two objects one with luminosity and the other recieving

Question 9

Temperature and Velocity share what in common?

Answer 9

Both are proportional

Question 10

Is the solar constant always constant?

Answer 10

No

Question 11

Blackbody

Answer 11

Idealized substance that radiates at all wavelengths with maximum efficiency

Question 12

Effective temperature

Answer 12

Average temperature of a body at which it radiates energy. (ex. temp of earth w/o atmoshphere)

Question 13

What is the effective area for absorbing radiation from the sun?

Answer 13

pi(R)^2

Question 14

Planck function

Answer 14

dependence of radiative flux on wavelength

Question 15

Wien’s Law

Answer 15

gammamax~2898/Teff

Question 16

Stefan-Boltzman Law

Answer 16

S=sigmaT^4, sigma=boltzmann’s constant

Question 17

Teff of a planet?

Answer 17

fourth root((S/4)(1/sigma)(1-albedo))