Topics include major events, persons, and issues spanning the period from the African heritage to contemporary times. Students survey the evolution of African American expressive culture in music, literature, film, art, and dance. The course includes lectures, discussions, and video presentations.
Measure the width of your hair with a laser pointer Play with lasers and learn about diffraction Jul 25, — All you need is a dark room, a laser pointer, some cardboard, tape and a little bit of math.
I took samples from willing volunteers. Then I measured how they scattered the light from a laser pointer with the help of fellow writer Chris Crockett. Here is how you can do it too: Make a frame that can hold your hair. I cut a square of cardboard about 15 centimeters roughly six inches wide, and then cut a small rectangle inside it.
My inside cutout was about one centimeter 0. Take a human hair, maybe from your own head, or from a willing volunteer. Make sure it is long enough to tape at both ends of your inside rectangle.
In my case, each hair had to be at least 5 centimeters long to make sure I could tape it at both ends. Tape the hair, as tight as you can, at the top and bottom of your frame, so that the hair runs through the middle of the inside cutout.
In a dark room, stand more than a meter more than three feet away from a blank wall. Hold up the frame with your hair, and shine a laser pointer at the wall from just behind the hair, making sure it hits the hair along the way.
You will see the light scatter to the sides as you hit the hair with your laser pointer. Diffraction is the bending that takes place when a wave of light encounters an object, such as a human hair or a slit in a piece of paper.
Light can act as a wave, and when it encounters the hair it splits into a regular pattern of lines. It will create a scatter pattern you can see on the wall.
The size of the pattern from this diffraction is related to the size of the object that caused the scatter. This means that by measuring the size of your light scatter, you can — with a little math — figure out the width of your hair. Measure the distance from your hair to the wall where you are shining your pointer.
Check the wavelength of light produced by your laser pointer.
A red laser pointer will be about nanometers and one issuing a green light will be about nanometers. Usually this is listed on the laser pointer itself. Measure the light scatter on the wall. Also measure this in centimeters. Now, you have all you need to figure out how thick your hair is.
It will help to make sure that all of your numbers are in the same units. I converted all of my numbers to centimeters. My numbers looked like this: Distance between my hair and laser and the wall: Average light scatter of the hairs of the seven people I sampled: Then, I put the numbers into the equation provided in the video: In this equation, D is the diameter of your hair.
Since I measured to the first dark gap, m is one. Thethe Greek letter lambda, is the wavelength of the laser, in this case, nanometers or 0.
The is the angle at which the light scatter occurs.Simonton's comments are likely to draw a strong reaction, both in and out of the science world. It's been the geniuses among us that have driven science forward for thousands of years, after all.
Diffraction AP Physics B. schwenkreis.comerence PHASE. Diffraction When light OR sound is produced by TWO sources a pattern results as a result of interference. Interference Patterns Diffraction is normally taken to refer to various phenomena which occur AP Physics B - Diffraction.
is and in to a was not you i of it the be he his but for are this that by on at they with which she or from had we will have an what been one if would who has her. AFAM Intro to African American Studies This course provides an overview of African American history and culture.
Topics include major events, persons, and issues spanning the period from the African heritage to contemporary times. Diffraction Hair Lab Ap Physics Essay Sample Purpose: The Purpose of this experiment is to find the width of a piece of hair using diffraction pattern created by a thin film.
Hypothesis: If the hair is human it will have a width of m. Type or paste a DOI name into the text box. Click Go. Your browser will take you to a Web page (URL) associated with that DOI name. Send questions or comments to doi.