Lab Report Day 9 - Electric Fields

Active Physics

This is the active physics we do in the beginning of class. (We finished it after class.)

Electric Field

Those are some features of an electric field. An electric field is caused by some charge particles. The magnitude of an electric field depends on the charge. The magnitude of an electric field also depends on the distance. Not until a charge is placed in an electric field does it experiences an electric force.

3D Models of Electric Field

A 3-D negative charge

Professor Mason use the polystyrene plate to make two hemispheres which represent positive and negative charges. A positive electric field points out, and the negative electric field points in. When we put the two opposite charge together, the positive electric field will go to the negative charged electric field. From this model, It helps visualize a positive charge and a negative charge.

We derive the formula for electric field

Doing some exercises.

Plotting the electric field vs. distance graph. We can see that it is a hyperbola shape. 

Some exercises.

Superposition of Electric Field Vectors

Using Excel to calculate the net electric field (using equation E=Kq/r^2)

We change the distances from 0.5 to10.0 cm with increment of 0.5. Using the information calculated on the spreadsheet, we get the net electric field. 

Extended Charge Distribution

 

Some Calculations. From Excel, we find that the electric field is 5.97*10^4. In here, we make some calculations and find that our value is 5.99*10^4, which is almost exactly what we get from the excel.

Electric Field Hockey

The electric hockey game is interesting. Some how I find that we can pause and remove the charge that we have no use, and the total charge will be deducted.

Conclusion

In today's class, we learn what a positive and negative charge look like. We also learn that since electric field is a vector, we can add the electric field together.