Question Detail
Question
An electron (mass 9.11e-31 kg) with a horizontal speed of 1.2e7 m/s moves into a region with a constant vertical force of 4.5e-16 N. Determine the vertical deflection after moving 30 mm horizontally.
Correct Answer
Option D is the correct answer.
Detailed Explanation
First, find the time to travel 30 mm horizontally: t = (0.03 m) / (1.2e7 m/s) = 2.5e-9 s. Vertical acceleration: a = F/m = (4.5e-16 N) / (9.11e-31 kg) ≈ 4.94e14 m/s². Vertical deflection: y = 1/2 * a * t^2 = 0.5 * 4.94e14 * (2.5e-9)^2 ≈ 0.00154 m or 1.54 mm.
Hint
Treat horizontal and vertical motions independently. Find time from horizontal motion, then use kinematics for vertical motion.