1. Calculating the Electric Field Method #2 Large point charges generate the electric field The field is stronger the closer you are to the charge, and weaker as you move away IF you know the value of point charges, the field can be calculated based on distance.

2. Calculating the Electric Field Method #2 Strength of the Electric Field based on a point charge: ◦ k = 8.99 x 10 9 ◦ q = point charge ◦ r = distance away from the point charge

3. Example 3 A point charge (q = +9.50 x 10 -8 C) is generating part of the electric field. A.Calculate the strength of the electric field 2.00 m away from this charge. B.Calculate the strength of the electric field 5.00 m away from this charge. C.How far away from this point charge must you be to experience an electric field E = 100 N/C?

4. Example 4 Two point charges (q 1 and q 2 ) create a right triangle with point P. The point charge q 1 has a charge of +7.00 x 10 -8 C while point charge q 2 has a charge of -5.00 x 10 -8 C. Calculate the net electric field created by these two point charges at point P. q1q1 q2q2 P 0.520 m 0.300 m