An electron is projected with an initial speed v0 = 1.60 * 106 m>s into the uniform field between two parallel plates (Fig. E21.29). Assume that the field between the plates is uniform and directed vertically downward and that the field outside the plates is zero. The electron enters the field at a point midway between the plates. (a) If the electron just misses the upper plate as it emerges from the field, find the magnitude of the electric field. (b) Suppose that the electron in Fig. E21.29 is replaced by a proton with the same initial speed v0. Would the proton hit one of the plates? If not, what would be the magnitude and direction of its vertical displacement as it exits the region between the plates? (c) Compare the paths traveled by the electron and the proton, and explain the differences. (d) Discuss whether it is reasonable to ignore the effects of gravity for each particle.

Physics 211, Week 9 Notes PSU: Fall term Chapter 10: Angular Position: To describe the rotation of a rigid body about a fixed axis, called the rotation axis, we assume a reference line is fixed in the body, perpendicular to that axis and rotating with the body. We measure the angular position of this line relative to a fixed direction. When theta is measured in radians: Where s is the arc length of a circular path of radius r and angle theta. Radian measure is related to angel measure in revolutions and degrees by Angular displacement: A body that rotates about a rotation axis, changing its angular position from one degree to another, undergoes an angular displacement: (θ f θ) i angular displacement