doppler

In this picture, the ducks are swimming through the water and making waves. Since the duck is swimming faster than the wave it is creating it will all pile up in front of the duck. This piling of waves is called the Doppler effect. This happens with sound waves also. When a car moves toward you, the frequency changes because of the pile up of waves. Breaking the sound barrier was achieved when airplane designers put a point of the plane. Once an object moves faster than the sound waves it produces the waves make a v shaped behind the object. This is seen in the picture.

magnet in action

This is a picture of the speakers for my computer. Speakers are a good example of magnets in action. Inside the speakers, there is a magnet and a copper coil. The coil receives an electrical signal from my computer. As the electricity passes through the coil it causes the coil to turn into an electromagnet. Depending on the current flow in the coil, the magnet will either attract or repel the coil. This makes vibrations, which make sound. Better speakers have better magnets because that allows for more pull or push from the speakers.

meter

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

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.

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.

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.

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.