Tuesday, April 23, 2013
Motor Blog
During class we learned how to make a simple motor using a battery, rubber band, magnet, two paperclips, and come copper wire. The two paperclips were attached to either side of the batter by the rubber band. The copper wire was coiled and was held in the air above the magnet, which was stuck to the battery, by the two paperclips attached to each side of the magnet. This was the setup of our motor. The battery caused electrons to flow through the copper wire, which reacted to the magnetic field surrounding the magnet. The paper clops acted as conductors as well as a source of suspension for the wire. In order for charges to flow into the wire, the top layer of the wire needed to be scraped off in order to allow charges to run through the copper wire and complete the circuit. The armature needed to be scraped only on one side so that the wire would turn consecutively in one direction. If the wire had been scraped on both sides then it would simply turn back and forth. The motor turns simply because a current carrying wire is feeling a force from a magnetic field. If the current was flowing from left to right then the motor would turn coming towards you. If the current was flowing from left to right then the coils would move away from you. If you attached wheels to either end of the copper wire then it could be used like a car. If you attached blades instead then the motor could be used as a fan or perhaps as a blender or blending sort of contraption.
Tuesday, April 16, 2013
Magnet Resource
Monday, April 15, 2013
Unit 6 Reflection
This unit in physics we learned about charge, polarization,
and electric fields! We learned how real life situations such as hair standing
up after pulling a sweater over it, or why a balloon sticks to a wall after
rubbed against hair, is so.
Charges:
Charges are such by the make up of protons (positive ions) and/or
electrons (negative ions). Protons and electrons attract each other while
protons and protons or electrons and electrons repel each other. There are
three ways that an object could be come charged: friction, direct contact, and
induction. When you pull a sweater over your head, the sweater steals electrons
from your hair through friction. When this happens your hair is filled with
protons, since protons and protons repel each other, your hair stands up!
Polarization:
When discussing polarization, it is important to recognize
what a conductors and insulators are. Conductors let charges move through them,
insulators stop charges from moving. An object becomes polar when the charges
are separated. For example, if you stuck a rod of electrons near a neutral
object, all of the protons would move closer to the rod and the electrons would
move further away from it. When the negative and positive ions are separated
like this, the object is polarized. This is the reason that saran wrap wont
stick to metal bowls. Metal is a conductor and will send all charges to the
ground whereas glass and ceramic bowls will polarize.
We applied all that we learned about electricity to everyday
usage. We learned about lightning rods, light bulbs, circuit breakers, outlets,
and more!
Lightning rods:
We learned that lightning rods protect structures because of
their ability to prevent fires by their ability to send charges from lightning
to the ground. Lightning rods are pointy metal rods that are placed on the
roofs of buildings. Protons collect of the points of the rods and when
lightning strikes they attract the negatives charges coming towards the ground
from the clouds. When the lightning strikes the rods all the charges are send
to the ground through a cable that is connected to the bottom of the rod and
the ground.
Light Bulbs:
One of the many labs we did this unit required us to light a
light bulb using only a battery and some wire. Through this lab we learned that
the wire must be connected to the bottom of the bulb and the side of the bulb.
These two places are where the wires need to be in order to complete the
circuit and light the bulb. Similarly we learned that the wire in the middle of
the bulb is called the filament. Based on thickness and length the filament
will have either a high or low resistance and will determine how much current
can run through it, affecting how bright the bulb is.
Circuit Breakers:
In this unit of physics we learned why circuit breakers
commonly trip when you use too many appliances. Circuit breakers are wired as series
circuits, which mean as more things are used the current remains the same,
while the resistance increases. On the contrary houses are wired in parallel so
when you use more appliances, the overall current being used increases. When
this current gets too high it could potentially start a fire. In order to prevent
a fire from happening, the circuit breaker trips. The circuit breaker flips a
switch in the circuit and stops all appliances from working.
Outlets:
This unit we learned about voltage and how our outlets in
America are 120-volt outlets. We learned that outlets in Europe have a higher
voltage so when we take our appliances to Europe using them is actually
dangerous because our appliances are not designed to handle the amount of volts
that European outlets emit.
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