Physics of me
In this project we got to learn about any physics related event/thing we wanted to. I choose to learn about how light bulbs work. I soon realized that in order to understand light bulbs I would also need to understand circuits, and in order to understand circuits I needed to understand batteries. It was a lot more complicated than I expected, but I learned a lot and found a new appreciation for LEDs. This project taught me that I'm pretty good at researching subjects and cross referencing information as evident by the citation I have on my essay. I choose to put them where they were because that was where the websites most contributed to my essay, but most of those citation covered the entire subject; When two sources gave conflicting information I would find a third source to settle the debate. Usually the disconnect was simply a poor choice of words, but It never hurts to check! One thing that I need to improve on is my tendency to need to explain everything. My final essay was a lot more ramble-y and long than it should've been, and most of the essay wasn't even about light bulbs. In the future I will only cover the decided on subject in my articles. If someone wanted to know about circuits they won't look up how batteries work. so I can assume anyone who is reading the article already knows the background information.
Document:
Nicholas Jennings
9th grade physics
Dr. Cate
9/9/15
The Physics of light bulbs
Light bulbs are one of the most useful inventions humanity has even made. They give us light, without forcing us to deal with the hazards of fire, but how does this “flameless fire” work? Well, the light bulb part of a circuit begins with the input of an electrical current through an input at the bottom of the device. The current travels through a conductor to the other end of the circuit. However, the conductor stops about a quarter way through the circuit and is replaced with a filament metal such as tungsten. As the electrons that make up the current pass through the filament, they bump into the filament’s atoms, which shift around and generate heat energy. When the atoms gain heat energy, their electrons temporarily move up to another rung of orbit. The electrons are almost immediately pulled down into their standard orbit by the electromagnetic force. As they descend, the electrons release the extra energy as a light photon.
It’s also important to know that the lightbulb is not filled with air but an inert gas, most commonly argon. This stops the filament from catching fire because there is no oxygen to fuel the fire. This type of lightbulb (called an incandescent Bulb), is considered one of the least energy efficient bulbs available. This is because while some of the heat energy created by the filament becomes light, most of the energy stays as heat. Using lumens (a measurement of light), Incandescent bulbs generate around 15 lumens per watt, while LEDs can generate up to 100 lumens per watt.
A light Bulb’s circuit acts similar to any other circuit, with the tungsten filament as a resistor. The circuit begins with a battery. In a “full” battery the electrons are pushed to the negative side of the device. The electrons will naturally want to even themselves out, however they cannot move through the center of the battery because it is filled with fluid that the electrons cannot pass through. Therefore they must take the long route through the entire circuit. The force at which these electrons leave the battery is called voltage. The amount of electrons that are moving through the circuit at once is can be measured in amperes (amps). The voltage times the amps is called the wattage of the circuit. On the electrons journey around a circuit, they will occasionally bump into one of the conductors atoms and get slowed down, but this happens rarely on conducting metals so the electrons will encounter very little resistance(ohms). However, if the electrons need to pass through a less conductive metal (such as a light bulb filament) more resistance is put on the electrons. Because voltage describes the initial force on the electrons, ohms describes the loss of speed, and amps describes the actual speed, all three variables are closely related. This relationship is described in Ohm’s law, most commonly seen as R=V/I, or resistance=voltage/amps.
Once the electrons have completed the circuit, return to the battery through the positive end begin to balance out the battery. The process will continue until the electrons in the battery even themselves out, or the circuit is opened. This occurs when (usually by flicking a switch) the circuit ceases to be a closed shape, and becomes a line, with a beginning and end. If you think of a circuit as a water pipe with a pump supplying the force, opening a circuit is like clogging the pipe. The electrons at the end of the line can’t be moved, so none of the electrons can move.
Word problem: A crazed lunatic has taken you captive and is forcing you to hold an incandescent lightbulb in your hand for 5 minutes. He is however, giving you the chance to go free, if you can tell him how many lumens the light bulb is producing. The bulb’s circuit is powered by a 10 volt battery and has no resistors attached, but due to his lack of well made wires (he is a crazy person after all) the circuit still has 2 ohms of resistance. If the Lightbulb is using all the watts available to it, how many lumens it is giving off? Here are some equations that may help:
voltage = current(amps) * resistance(ohms), or v=ir
Power(watts) = current(amps) * voltage or p=iv
Answer: 750 lumens
Document:
Nicholas Jennings
9th grade physics
Dr. Cate
9/9/15
The Physics of light bulbs
Light bulbs are one of the most useful inventions humanity has even made. They give us light, without forcing us to deal with the hazards of fire, but how does this “flameless fire” work? Well, the light bulb part of a circuit begins with the input of an electrical current through an input at the bottom of the device. The current travels through a conductor to the other end of the circuit. However, the conductor stops about a quarter way through the circuit and is replaced with a filament metal such as tungsten. As the electrons that make up the current pass through the filament, they bump into the filament’s atoms, which shift around and generate heat energy. When the atoms gain heat energy, their electrons temporarily move up to another rung of orbit. The electrons are almost immediately pulled down into their standard orbit by the electromagnetic force. As they descend, the electrons release the extra energy as a light photon.
It’s also important to know that the lightbulb is not filled with air but an inert gas, most commonly argon. This stops the filament from catching fire because there is no oxygen to fuel the fire. This type of lightbulb (called an incandescent Bulb), is considered one of the least energy efficient bulbs available. This is because while some of the heat energy created by the filament becomes light, most of the energy stays as heat. Using lumens (a measurement of light), Incandescent bulbs generate around 15 lumens per watt, while LEDs can generate up to 100 lumens per watt.
A light Bulb’s circuit acts similar to any other circuit, with the tungsten filament as a resistor. The circuit begins with a battery. In a “full” battery the electrons are pushed to the negative side of the device. The electrons will naturally want to even themselves out, however they cannot move through the center of the battery because it is filled with fluid that the electrons cannot pass through. Therefore they must take the long route through the entire circuit. The force at which these electrons leave the battery is called voltage. The amount of electrons that are moving through the circuit at once is can be measured in amperes (amps). The voltage times the amps is called the wattage of the circuit. On the electrons journey around a circuit, they will occasionally bump into one of the conductors atoms and get slowed down, but this happens rarely on conducting metals so the electrons will encounter very little resistance(ohms). However, if the electrons need to pass through a less conductive metal (such as a light bulb filament) more resistance is put on the electrons. Because voltage describes the initial force on the electrons, ohms describes the loss of speed, and amps describes the actual speed, all three variables are closely related. This relationship is described in Ohm’s law, most commonly seen as R=V/I, or resistance=voltage/amps.
Once the electrons have completed the circuit, return to the battery through the positive end begin to balance out the battery. The process will continue until the electrons in the battery even themselves out, or the circuit is opened. This occurs when (usually by flicking a switch) the circuit ceases to be a closed shape, and becomes a line, with a beginning and end. If you think of a circuit as a water pipe with a pump supplying the force, opening a circuit is like clogging the pipe. The electrons at the end of the line can’t be moved, so none of the electrons can move.
Word problem: A crazed lunatic has taken you captive and is forcing you to hold an incandescent lightbulb in your hand for 5 minutes. He is however, giving you the chance to go free, if you can tell him how many lumens the light bulb is producing. The bulb’s circuit is powered by a 10 volt battery and has no resistors attached, but due to his lack of well made wires (he is a crazy person after all) the circuit still has 2 ohms of resistance. If the Lightbulb is using all the watts available to it, how many lumens it is giving off? Here are some equations that may help:
voltage = current(amps) * resistance(ohms), or v=ir
Power(watts) = current(amps) * voltage or p=iv
Answer: 750 lumens