PHYS 1404: Solar System; Chapter 03 HW

Each of the following items states a temperature, but does not tell you whether the temperature is measured on the Fahrenheit, Celsius, or Kelvin scale. Match the items to the appropriate temperature scale.

(3 Diagrams, with a thermostat) 1st Diagram (Left) - A hot summer day might be 100 - Ice Cream is stored in freezers at 26. 2nd (Middle) - Water freezes into ice at 0. - A typical room temperature is 24. - Liquid boils at 100. 3rd (Last) - The coldest possible temperature is 0. - Water boils into gas phase at 373.15

Each diagram below shows a pair of spectra with a set of spectral lines. The top spectrum always shows the lines as they appear in a spectrum created in a laboratory on Earth ("Lab") and the bottom spectrum shows the same set of lines from a distant star. The left (blue/violet) end of each spectrum corresponds to shorter wavelengths and the right (red) end to longer wavelengths. Rank the five stars based on the Doppler shifts of their spectra, from largest blueshift, through no shift, to largest redshift.

(Diagram and the I am describing the answers in order from left to right) Look at the lab results and star results. The lab results all stay the same. Now look at the star results. They are all different. Now pay attention to the last line on the star results. Put in order from blue shift to red shift. The last line that shifted most towards the blue area is the first answer. you need to put it in order from the line that moves close to the blue area, all the way to the line that moved closer to the red area. The star and lab results that are the same goes in the middle.

The diagrams below each show the motion of a distant star relative to Earth (not to scale). The red arrows indicate the speed and direction of the star's motion: Longer arrows mean faster speed. Rank the stars based on the Doppler shift that we would detect on Earth, from largest blueshift, through no shift, to largest redshift.

(Diagram from left to right) (The answers will be descriptions of the figures in order) Largest Blueshift to Largest Redshift ( Left to Right) - Longest red arrow point to earth - Shortest red arrow point to earth - Red arrow pointing in a complete opposite way - Shortest red arrow point away from star and earth. -Longest red arrow point away from star and earth.

The law of physics state that a magnetic field must accompany a changing electric field, and a change in one must create a change in the other. Together, electric and magnetic fields make up electromagnetic waves, which carry energy and information from one part of the universe to another. Electromagnetic waves share many properties with ordinary waves, but they also have a number of unique characteristics. Using the figure below and your knowledge from Parts A and B, complete the following statements about the specific properties of electromagnetic radiation.

*ANSWERS* Electromagnetic waves consist of co-oscillating electric and magnetic *fields*. The wave amplitudes are directed *perpendicular* to the direction of wave motion. Energy and information flows *parallel* to the direction of wave motion. Electromagnetic waves are able to travel through a *vacuum*. Electromagnetic waves travel at a speed of *300,000 km/s*.

What is the wavelength of a 100-MHz ("FM 100") radio signal?

- 3m

If you throw a rock into a pond, it creates a wave in the water. What is responsible for creating an electromagnetic wave?

- A vibrating charged particle

Which of the following statements are true? Check all that apply. Visible is named this because we can see these waves. Infrared is named for the part of the spectrum with frequencies less than those of red light. Radio is named because of the way we hear these waves. Ultraviolet is named for the part of the spectrum with frequencies greater than those of violet light. X-ray is named this because it is the least understood part of the spectrum. Gamma is named for its discoverer, Frederic Gamma.

- Visible is named this because we can see these waves. - Infrared is named for the part of the spectrum with frequencies less than those of red light. - Ultraviolet is named for the part of the spectrum with frequencies greater than those of violet light.

Electromagnetic radiation: A. is the same as a sound wave. B. has only the properties of waves. C. can only travel in a dense medium. D. has nothing in common with radio waves. E. can behave both as a wave and as a particle.

- can behave both as a wave and as a particle.

Colors appear different to us because of their photons' different:

- frequencies.

The Doppler Effect is a phenomenon that allows one to measure an object's:

- radial motion.

Knowing the peak emission wavelength of a blackbody allows you to determine its ________.

- temperature

The wavelength at which a blackbody radiates most depends on its:

- temperature.

The total energy radiated by a blackbody depends on:

- the fourth power of its temperature.

Stars like our Sun emit most of their light in which part of the electromagnetic spectrum?

- the visible

What does the phenomenon of diffraction demonstrate?

- the wave nature of light

Which of these is constant for ALL types of electromagnetic radiation in a vacuum?

- velocity

Which type of radiation can be observed well from Earth's surface?

- visible

The two forms of electromagnetic radiation that penetrate the atmosphere best are:

- visible and radio waves.

An important line of hydrogen occurs at a rest wavelength (as measured in a laboratory) of 656 nm (a nanometer (nm) is a billionth of a meter). Each diagram below has this line labeled with its wavelength in the spectrum of a distant star. Rank the motion of the stars along our line of sight (radial motion) based on their speed and direction, from moving fastest toward Earth, through zero (not moving toward or away from Earth), to moving fastest away from Earth.

Fastest toward Earth. (1.) 646 nanometers. (2.) 650 nanometers. (3.) 656 nanometers. (4.) 657 nanometers. (5.) 663 nanometers. Fastest away from Earth.

Light is a wave, and, like all waves, it is characterized by specific physical characteristics. Identify the key physical characteristics of a wave in the figures below. Figure A shows a wave as a function of time, and Figure B shows a wave as a function of space.

Figure A: (Starting on the left at top) - Wave Period (The right one on the top) - Amplitude (Bottom one) - Undisturbed State Figure B: (Starting on the left at top) -Wavelength (The right one on the top) -Amplitude (Bottom one) - Undisturbed State

Consider the following objects. The wavelength emitted by the object is highlighted in red on the spectrum bar below the image. Decide which objects emit radiation that can penetrate Earth's atmosphere and reach the surface, and drag the objects into the appropriate bins.

Object's radiation can reach earth: - "Yellow Ball" - "Red Flame" Object's radiation cannot reach earth surface: - "Purple Blue Flame" - "Purple Flame"

Listed following are various physical situations that describe how light interacts with matter. Match these to the appropriate category.

Transmission: - Cell Phone signals pass through walls. - Visible Light meets clear glass. Absorption: - Visible Light does not pass through a black wall. - Blue light hits a red sweater. Reflection or scattering: - Red light hits a red sweater - White light hits a white piece of paper Emission: - Light comes from a light bulb - Light comes from your computer screen

A wave's velocity is the product of the

frequency times the wavelength of the wave.