An electron, starting from rest and moving with a constant acceleration, travels 2.0 cm in 5.0 ms. What is the magnitude of this acceleration? A) 2.5 km/s² B) 0.80 km/s² C) 1.6 km/s² D) 1.3 km/s² E) 3.2 km/s²

Question

Quizplus · Accepted Answer

First, we need to find the electron's acceleration using the equation:
distance = 1/2 x acceleration x time^2
Since the electron starts from rest, its initial velocity (u) is zero. Therefore we can use the simplified equation:
distance = 1/2 x acceleration x time^2
Plugging in the given values:
2.0 cm = 1/2 x acceleration x (5.0 x 10^-3 s)^2
Solving for acceleration:
acceleration = (2 x 2.0 cm) / (5.0 x 10^-3 s)^2
acceleration = 1.6 x 10^7 cm/s^2
Converting to km/s^2:
acceleration = 1.6 x 10^7 cm/s^2 x (1 m/100 cm)^2 x (1 km/1000 m)
acceleration ≈ 1.6 km/s^2
Therefore, the answer is C.

An Electron, Starting from Rest and Moving with a Constant