An electron, starting from rest and moving with a constant acceleration, travels 2.0 cm in 5.0 m/s. 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

The equation for the distance traveled under constant acceleration is:

d = 1/2 a t^2

where d is the distance traveled, a is the acceleration, and t is the time elapsed.

In this problem, we are given d = 2.0 cm = 0.02 m and t = 5.0 s.

We can rearrange the equation to solve for a:

a = 2d / t^2

Substituting our values, we get:

a = 2(0.02 m) / (5.0 s)^2 = 0.0016 m/s^2

Converting to km/s^2, we get:

a = 0.0016 m/s^2 * (1 km / 1000 m)^2 = 1.6 km/s^2

Therefore, the magnitude of the acceleration is 1.6 km/s^2, or choice C.

An Electron, Starting from Rest and Moving with a Constant