Two point charges carrying charges q1 = +3 μC and q2 = −4 μC are fixed on the x − y plane at positions (x1 = 3.5 cm, y1 = 0.5 cm
) and (x2 = −2 cm, y2 = 1.5 cm) respectively. a) Find the magnitude and direction of the electrostatic force on charge q2.
b) Where in the x − y plane can you place a third charge q3 = 4 μC, such that the net electrostatic force on charge q2 is zero?
The Gravitational spring energy(Us) is equal to 1/2kx^2. So we have x as .2 m and Us as 4 N. So 4 N = 1/2 * k * .2^2. So now we solve for K and get 200 N/m.