Question

1. An electron is shot at 10 m/s⁶ between two parallel charged plates. If the field intensity E between the plates is 1 KN/C, where will the electron strike the upper plate? Assume vacuum conditions.
2. Figure 2 below shows a triangular array of three point charges, Q₁ = 1.0 x10^-6 c, Q₂ = -2.0 x10^-6 c and Q₃ = 3.0 x 10^-6 c. The height of the triangle is 0.300 m and the length of the base is 0.400 m. Find the electric potential V of these source at the midpoint P of the base of the triangle.

Answer 1

1)

$A=E_k,$

$eEd=\frac{mv^2}{2},$

$d=\sqrt{\frac{mv^2}{2eE}}=53~mm.$

2)

$r_1=r_2=0.2~m,~r_3=0. 3~m,$

$U=k(\frac{q_1}{r_1}+\frac{q_2}{r_2}+\frac{q_3}{r_3})=45\cdot 10^3~V.$