Sunday, May 10, 2009

Color


In this picture, the daisy is yellow because it is being hit by white light and yellow light is reflected off the daisy. Red and Green light is really being reflected off the daisy because when you mix Red and Green light you get yellow. In your eyes, there are three cones that pick up Red, Green or Blue. Depending on the intensity of these three colors all colors can be made. This is how televisions and computer screens work.

Tuesday, March 17, 2009

meter


This a picture of my electricity meter. Sorry my camera does not have flash so i had to use a flash light.

Sunday, March 8, 2009

lights


This is a picture of a compact florescent light bulb in my house. It is more energy efficient than it counterpart the incandescent light bulb. The incandescent light bulb differs because it uses the high resistance of the Tungsten wire to produce heat and light. The florescent light works with gas so it uses less energy. A light bulb works because it completes the circuit. When you plug a light bulb into the socket, 120 Volts difference travels through the circuit until the light bulb takes the volts and turns it into power. (P=IV) The current in the wire depends on how many other things are connected to the power source. Because it is hooked up in parallel, the current will increase with the amount resistors are hooked up.

Saturday, February 14, 2009

This weekend, I went the Punahou Carnival and saw a lot of physics. The ride called the ring of fire is a ride that takes you in a loop. It slowly speeds up until you only have enough speed to make a full revolution. This ride reminded me of centripetal force. The equation for Fc=mass times velocity squared over the radius of the circle. The roller coaster feels normal force from the tracks and that helps the centripetal force. At the highest point at the slowest speed the normal force of the track is zero.

Sunday, February 1, 2009


In this picture there are two different sized wrenches. If you want to maximize the amount of torque you can produce, you would want to use the longer one. In the equation lever arm times the force equals torque, if you increase the lever arm you can increase the torque. That’s why it is easier to loosen a bolt with a long handle than a short handle. If you need more torque on a bolt, all you need to do is lengthen the lever arm.

Monday, January 26, 2009

extra credit


In the video, I used a charged balloon to make the water bend. This happens because as the balloon rubs against my head, it gains electrons from my hair. The rubber balloon is an insulator so all the electrons stay in one place and don’t spread around the balloon. The electrons cause a negative charge on the balloon. When the balloon comes close to the water, the positive charges in the water move closer the balloon because opposites attract. The negative charges move away from the balloon because like charges push each other away. This polarization of the water causes it to bend because the pull of the positive water and negative balloon is stronger than the repulsive forces of the negative charges.

Sunday, January 25, 2009

static magic


In this picture, I wanted to see the effects of static electricity. I rubbed a balloon on my hair and put it on the wall and it magically stayed on the wall. I used friction to make static electricity. When I rubbed the balloon to my head, the friction that was created caused some of the electrons from my head jump to the balloon. Since the balloon isn’t a conductor the negatively charged electrons stayed in a concentrated area. The negatively charged area on the balloon touches the wall and all the positive charges on the wall want to come closer to the balloon and all the negative charges want to go away from the balloon. This causes something called polarization of the wall because now there are two different poles a positive and negative charge but the net charge is still zero.