# Chapter 8 Homework for NSCI 110

This NSCI 110 assignment is to be submitted on-line at least one half hour before class begins.

Name (first and last please, do not use quotation marks):

Section number:

Place your response for each item in the corresponding text box. Include all steps in numeric calculations. You may change your mind as often as you wish. When you are satisfied, click the SUBMIT HOMEWORK button at the bottom of the page.

Applying the concepts at the end of the chapter. You are required to do all odd problems. The even problems are also recommended.

Questions for thought on p. 207.

Question 1.
What determines if an electromagnetic wave emitted from an object is a visible light wave or a wave of infrared radiation?

Question 6.
One star is reddish, and another is bluish. Do you know anything about the relative temperatures of the two stars? Explain.

Question 8.
Why does a highway sometimes appear wet on a hot summer day when it is not wet?

Question 14.
Why are both the photon model and the electromagnetic wave model accepted today as a single theory? Why was this so difficult for people to accept at first?

Parallel Exercises for this chapter. These problems are taken from Group B. For some problems, you will find a similar problem in Group A with the solution given in appendix D. Please show your work. Partial credit will be awarded.

Problem 1.
Expressed with 6 significant figures, the speed of light while traveling through a vacuum is 2.99792x10^8 m/s. (a) Calculate the speed with the same precision in air at 30 degrees C? (b) While traveling through air at 0 degrees C?

Problem 2.
How much time is required for reflected sunlight to travel from the Moon to Earth if the distance between Earth and the Moon is 3.85 x 10^5 km?

Problem 5.
The speed of light through a transparent substance is 2.00 x 10^8 m/s. What is the substance?

Problem 8.
The wavelength of light from a monochromatic source is measured to be 6.80 x 10^-7 m. (a) What is the frequency of this light? (b) What color would you observe?

Problem 10.
At what rate must electrons in a wire vibrate to emit microwaves with a wavelength of 1.00 mm?

Below is a space for your thoughts, including general comments about today's assignment (what seemed impossible, what reading didn't make sense, what we should spend class time on, what was "cool", what's happening in your life that you want your instructor to know about, etc.):