Question Detail
Question
An electron with speed 1.2 × 10^7 m/s moves horizontally into a region where a constant vertical force of 4.5 × 10^-15 N acts on it. The mass of the electron is 9.11 × 10^-31 kg. Determine the vertical distance it is deflected while moving 30 mm horizontally.
Correct Answer
Option C is the correct answer.
Detailed Explanation
Time = x/v = 0.03 / (1.2×10^7) = 2.5×10^-9 s. Acceleration = F/m = (4.5×10^-15)/(9.11×10^-31) ≈ 4.94×10^15 m/s². Deflection y = ½at² ≈ 0.5 × 4.94×10^15 × (2.5×10^-9)² ≈ 200 m.
Hint
Use constant acceleration motion vertically while horizontal speed is constant.