00:01
In this question, we have three negative point charges arranged in a vertical line.
00:05
You want to find a net electric field at point p.
00:10
Okay, so this is a question on kulom's law.
00:20
So using kulom's law, the electric field due to a point charge is one over for pi x lot or not, q over r square.
00:34
Okay so an e is a vector electric field is a vector okay so we have three electric field vectors okay we need to do vector some okay so we need to draw the electric field arrows so we have e2 pointing directly to to the negative charge and then e1 and e3 okay, the arrows, the length of the arrows don't represent many two here.
01:25
And then we also want to know the r.
01:28
Okay, so we have r2, r2 is 6 cm.
01:32
R1 and r3 are the same.
01:34
And okay, so to find r1 and r3, so we know that this is a right angle, triangle here.
01:42
You have the base xm, the height is the hipcm, the hypothalamus will be ncr.
01:48
Using pythagoras theorem.
01:51
So and if you look at the situation, e1 and e3 have the same magnitude.
02:10
Okay, so the vertical components, pencil out.
02:20
Okay, so you want the horizontal components...