First Place - Natural Category Broken Scenery Jessica Levasseur and Kaidi Liu, Naperville Central H.S., 440 Aurora Ave., Naperville, IL 60540 Teacher: Christine Pietrykowski The virtual image on the photo, unlike that of plane mirrors used in homes, is not a symmetric inverse image. The reason is that each tile on the wall acts as a single mirror. Each is inclined at a different angle, so the mirrors are not coplanar. Therefore, the normals of each tile are not parallel to each other, which results in different degrees of angles of reflection. So the virtual image formed on each tile does not form properly as a whole. The fact that each mirror shows a different angle of the picture explains why the picture does not appear identical. Each individual part in each mirror, though, is completely identical to the original image.
		First Place - Contrived Category Color Mixing Caitlin Morgan, John Burroughs School, 755 S. Price Rd., St. Louis, MO 63124 Teacher: J. Mark Schober It is obvious that there are only three different colors of light, but in the middle of the three beams, there is a big white spot. Why? Blue, red, and green are the additive primary colors. Below the white spot in the picture, blue and red mix to create magenta. To the right of the white spot, red and green mix to create yellow. And to the left of the white spot, blue and green mix to create cyan. When looking at the mixture of these three colors from a distance, the mixtures of the spots provide a complete range of colors, including white. Therefore, when the three beams of light intersect in the picture, the white spot becomes apparent.
		Second Place - Natural Category White Bronco Projectile Motion Aaron Gutting, John Burroughs School, 755 S. Price Rd., St. Louis, MO 63124 Teacher: J. Mark Schober I launched a small car off a ramp. To capture multiple images of the car, I placed a strobe light to the side of the setup, left the shutter open for half a second, and then launched the car. The car gains velocity as it rolls down the ramp. After the car has left the ramp, its horizontal velocity remains constant. After the car has left the ramp, there is no normal force, so the net gravitational force accelerates it in the Y direction, resulting in the shown parabolic motion. Also, when the front wheels leave the ramp, the resulting torque begins the car rotating. After the car leaves the ramp, there is no net torque, and the car rotates with a constant angular velocity of about 20 degrees per image.
		Second Place - Contrived Category Dancing Paper Bits on Drumhead Sharon M. Roberson and Elizabeth L. Whitlock, North Carolina School of Science and Mathematics, 1219 Broad St., Durham, NC 27715 Teacher: Loren Winters We used a computer to set off eight flashes covered with colored cellophane in a rainbow sequence, 5.5 milliseconds apart. When we hit the drum, a sound trigger picked up the sound and sent a signal to the computer interface to set off the flashes. The circles are white paper bits from a hole punch. We produced an antinode at the center of the drum where we hit it, thereby making the paper bits jump up the highest at that point. Toward the boundary of the drum, the displacement of the bits was the least, showing the presence of a node at the edge of the drum.
		Third Place - Natural Category The Physics of a Dive Rebecca R. Evans, Springbrook H.S., 201 Valleybrook Dr., Silver Spring, MD 20904 Teacher: Nazish Habib From the time the diver jumps from the board, up until the moment of suspension (shown in picture), the diver is building up potential energy. Upon descending, the diver’s kinetic energy increases and the potential energy decreases. The diver’s kinetic energy, right before she hits the water, should be the same amount as the potential energy at the moment of suspension. This is the law of conservation of energy. Newton’s third law is also demonstrated in this photo. As the diver exerts a force on the diving board, the diving board exerts a force on the diver, giving her enough energy to suspend in air and execute the dive.
		Third Place - Contrived Category Color Mixing by Subtraction Jenny Lowe, John Burroughs School, 755 S. Price Rd., St. Louis, MO 63124 Teacher: J. Mark Schober Each ruler has a different color, but when mixed, they transmit a spectra of color not limited to the four original. This is due to subtractive color mixing. Take, for example, the green color transmitted. When cyan and yellow rulers are combined, they make green. This is because the cyan ruler absorbs all the colors except green and blue. The yellow ruler absorbs all the colors except red, orange, yellow, and green. Therefore, green will be the color seen because color is determined by the particular frequency of light being transmitted. Subtractive coloring is commonly used with paints, inks, and dyes.
		Honorable Mention - Natural Category (Tie) Untitled Drew Altdoerffer, Whitesboro H.S., 6000 State Route 291, Marcy, NY 13403 Teacher: Ralph Greco The object, which is hanging from the car’s rearview mirror, is leaning toward the left side of the car while the car turns right. This happens due to the object’s tendency to want to continue in a straight line while the car rounds a turn due to its inertia. The reason for this is the car’s path in a circular direction to the right while the object hanging from the mirror has an inertial need to continue straight in the absence of an outside force.
		Rainbows Megan Stringer, Broadneck H.S., 1265 Green Holly Dr., Annapolis, MD 21401 Teacher: Allison Hapka Rainbows are created by the refraction and reflection occurring within raindrops in the atmosphere. Sunlight that is incident on the raindrop is refracted. The separation of colors in the rainbow is the result of dispersion, the separation of light into a spectrum. Each color is refracted at slightly different angles. At the back surface of the raindrop the sunlight undergoes total internal reflection. When leaving the raindrop, the light is once more refracted and dispersed.
		Honorable Mention - Contrived Category (Tie) A Balancing Act Melissa Dunigan, Homewood-Flossmoor H.S., 999 Kedzie Ave., Flossmoor, IL 60422 Teacher: Thomas Cavanaugh When Mike stands on his string bass, a center of mass exists for the two of them together. He needs to position the combined center of mass of himself and his bass in such a way that it is perpendicular to the spot that the bass touches the ground. Then he balances.
		Net Ashley Solomon, Glenbrook North H.S., 2300 Shermer Rd., Northbrook, IL 60062 Teacher: Nathan A. Unterman This picture was taken using three mirrors in front of the lens. These three mirrors formed an equilateral triangle. The base made a 30° angle with the horizontal. The man is framed by this primary triangle. At each corner, there are multiple reflections of reflections! As you can see, the bottom half of the man’s body is reflected on the top of his head. It also appears that this person is floating in the trees. This too is a result of the three mirrors, multiple reflections.

 

Thanks     Vernier. Participants in the AAPT High School Physics Photo Contest gain experience, knowledge, and exposure. And what do they gain by winning? Thanks to Vernier Software & Technology, a leader in the production of quality sensors, interfaces, software, and lab books, student winners and their teachers receive money prizes, gift certificates, and plaques. Thanks Vernier. Visit Vernier on the Web at http://www.vernier.com/.

Student winners received: First Place - $100 check and plaque Second Place - $75 check and plaque Third Place - $50 check and plaque Honorable Mention - $25 check Teachers of winning students received: For each winning student (First, Second, Third) the teacher receives $100 Vernier Software gift certificate or a plaque with the student's name. For multiple winners the teacher can choose a combination of gift certificate and plaque.