Alright i have two problems i need help with
Find the electric field at a point midway between two charges of +43.1 10^-9 C and +61.7 10^-9 C separated by a distance of 24.7 cm.
A Van de Graaff generator is charged so that the magnitude of the electric field at its surface is 2.8 104 N/C.
(a) What is the magnitude of the electric force on a proton released at the surface of the generator?
(b) Find the proton's acceleration at this instant.
The Attempt at a Solution
For the first one, I dont really know how to get the point in the middle. I got 9.1 x 10^3 N/C for the electric frield of the 61.7 c x 10^-9 and 6.4x10^3 N/C for the 43.1 c x10-9. So basicly what i need help with is the electric field at the mid-point.
For the 2nd one. I got part (a) right, i got 4.48 x10 ^-15 N. I need help getting the acceleration of the proton at that instant.