3/24 Week 5 day1 Electric Field

at the beginning of the class, the professor asked us to change the gravity situations to electric situations. what we did is in the photo.

in this photo, we combine the equation F=k*q_1*q_2/r^2 and E=F/q to find the E= k*q_2/r^2.

in this photo, we put a proton in the 3-D coordinate system and mark the directions of electric field, we can find that all directions deviate from the proton.

in this photo, we want to find the Electric field equation. and we have 5 steps in the photo.

Then in this photo, the professor ask us to predict electric vectors located and their directions. 

in these photos, we use the codes that professor gives us and use the equation to find

Then we begin to do the exercises about electric field. in this photo, we put two opposite balls which have + and another has -. and we should find the total E of a special position. That position is on the right side. we also use the equation:E=k*q/r^2 to find it.

in this photo, we change the position that we want to know. we place it on the middle of the two electric balls and find the E_total. in this question, we should find the x and y axis 's E and add them together. 

This is another exercise we did today, we also should find the E for every part on the line to the special point. this one is a little hard because we should find their distant r.  in the second photo, we use excel to find the E total is 59715 N/C.

 in this photo, we find the position of the middle of the line and find the E_total. We find the E_x and E_y first and add them. we find that the E_x is 0 and E_y is 110210 N/C

in this photo, we use another way to find the total E of the special position. what we did is in the photo, and we calculate that E_total=60000 N/C is same as what we got about 59715 N/C.



Conclusion:
Today in class, we learn what is electric field and how to express the electric field. We learn how to draw the lines in a electric field .and use equation E=kq/r^2 to find the how strong in an electric field.