#masteringphysics

Suppose electrons enter a uniform electric field midway between two plates at an angle θ0 to the horizontal, as shown in the figure (Figure 1). The path is symmetrical, so they leave at the same angle θ0 and just barely miss the top plate.

What is θ0? Ignore fringing of the field.

An electron has an initial velocity v0 = (9.0×104m/s) j . It enters a region where E^=(1.9 i + 7.4 j)×10^4 N/C.

a) Determine the vector acceleration of the electron as a function of time.

b) At what angle θ is it moving (relative to its initial direction) at t = 1.4 ns ? (counterclockwise from the initial direction)

a) Use Coulomb's law to determine the magnitude of the electric field at points A and B in the figure (Figure 1) due to the two positive charges (Q = 4.7 μC , a = 5.5 cm ) shown.

b) Use Coulomb's law to determine the direction of the electric field at points A and B

c) Are your results consistent with Fig.21-34b in the textbook?

You are given two unknown point charges, Q1 and Q2 . At a point on the line joining them, one-third of the way from Q1 to Q2 , the electric field is zero (see the figure (Figure 1)).

What is the ratio Q1/Q2?