Unit 6 Summary

Unit 6 Summary Blog Post

            Electricity and Charges

What did we learn this unit?

            Charges- There are three ways to create change in charges, friction, contact, and induction. The first two take them by touching, which steals electrons. Induction however does not touch, and uses its high amounts of energy to move electrons. The two types of charges are negative and positive. They are attracted to each other. They do hate being next to like charges though.

            Polarization- Is where charges separate, but the object as a whole stays neutral. This happens when something which is very charged comes into close proximity with a neutral item. As the distance increases the force decreases.

            Electric fields- The area around a charge can influence another charge. Electronics are put in an electric field inside a metal container, which blocks outside forces, by having forces from every direction.

            Voltage- is the electrical measure of Potential energy. A volt is how much PE an object has, and Voltage is the difference in PE two objects have.

            Circuits- To complete a circuit current must be able to flow from one end out of the power source, to back in. If at all there is a break in the wire in a series circuit the entire current will disappear. In a parallel circuit the power will still flow as long as the break happened after meeting the first light or appliance. Parallel circuits have fuses, because adding objects to the circuit increases current. A fuse works by breaking the circuit in case the wire becomes too hot. A series circuit has a certain amount of current, which diminishes with the number of lights/ appliances attached, due to resistance.

Formulas From the unit

            Power = Current (Voltage)

            Current = Potential energy / charge

            Current = voltage / resistance

            Coulomb’s law

Power = watts

            F=k Q1 (Q2) /d (d)

Things students often forget

·         That volts and voltage are two different things. A volt is the amount of PE, and voltage is the difference in PE.

·         Being polar does not mean the item has a charge.

·         Flow arrows point to what a positive atom would do.

·         The act of lightning is not induction, but rather the build up on the ground.

·         The same numbers of electrons that flow out of a battery come back in on the negative side.

How this relates to the outside world

            Electricity is an integral part of our daily lives, and having a simple understanding of it is crucial to better knowing the world around us. Parallel and series circuits, lightning rods, and dryer sheets are things we interact with daily. Knowing those makes us more able to take care of issues our selves, and opens the gates for new robot designs.

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