electronics 10 zchen: September 2014

Tuesday, September 30, 2014

5% Extra Credit on Celebration One

Monday, September 29, 2014

Day 10

ActivPhysics

Questions 1-9 were answered with the simulation below.

3+ Charge

Denser lines=Higher Force

1+ Charge

1- Charge

In this lab we first charge put a cylinder cage with aluminum foil inside. predicting which direction the aluminum foil will go.

But it only outside foil move up because the flux of inside is zero, the number of electric field coming in and electric out is the same.

Day 9

The three dimension model of a positive charged electric field which is represented by the bulge and negative charged electric field which is represented by a dip.

The positive electric field points outward, and the direction of negative electric field is inward. When we put the two electric field together, the positive electric field tends to move to the negative charged electric field.

Extended Charge Distribution

Derive formula from integration. We divided the rod into little pieces.

ActivPhysics

Electric Fields were furthered studied using ActivPhysics. Questions 1-6 were answered in the whiteboard picture below.

Electric Field Hockey

Day 8

In this lab, we rubbed the balloon with animal fur, then stick the balloon to the glass cabinet. by the experiment, we predicted that the balloon will stick in the glass because the balloon is charged by the animal fur with negative charge , and there is positive charge on the glass, they can be stick together.

If we peel two tape off the table and bring the non-sticky side of it toward each other, the tape will repel each other. The closer they are, the larger distance they will repel. And different side of tape to close to each other,

At the beginning of this experiment, we predicted that The relationship between force and distance r is inversely proportional.

The FBD about suspended ball.

By using LoggerPro, we find a graph that shows the relationship between electron force and distance, and find the values. In the lab, the theoretical value is 2, and our experimental value is 1.999. It is very close to it. The reason why it is not exact 2 is because we some times click the point not at the middle of the ball.

If two charges have same charge, then they will repel. If they are opposite signs, they will attract to each other.

The Van De Graff generator can charge other objects.

Professor Mason places a wig above the Van De Graff generator. the hair is sticking up. That is because the generator puts charges into the wig, then all the charges are same, they want to repel each other.

Then, Professor Mason puts a Franklin motor above the generator. then the Franklin motor immediately spins because the charge accumulated at the points. It is a conservation of momentum situation, the electrons streamed out of those points and moved the entire system.

Day 7

In the experiment sterling engine,some ice is putted on top of the sterling engine as cold reservoir, and put hot water as a hot reservoir under the sterling engine. The hot water supports energy into the system as system energy. Next, part of the energy that goes into mechanical to push the engine to work, and part of it is transferred to the Q, so it goes into the ice and melts it. The cycle can keep spinning because the temperature's different is same. actually，the solar platform is one of the examples. The sun provides the hotter temperature side and gourd represents the cooler side and that difference in temperature gets the sterling engine working. The efficiency of the theoretical efficiency is pretty high compare to other heat engine.