An electron, starting from rest and moving with a constant acceleration, travels 2 cm in 11 ms. What is?

Question

An electron, starting from rest and moving with a constant acceleration, travels 2 cm in 11 ms. What is the magnitude of this acceleration in km/s^2?

Answer 1

Let a be the acceleration. We have,

s = ut + 1/2.a.t^2

2 = 0 + 1/2.a.11^2 x 10^-6

2 = a.121.10^-6 / 2

a = 4 x 10^6 / 121 cms

= 0.33 km/sec^2

Answer 2

Use the standard distance equation for constant acceleration: d = vt + 1/2 at^2. d is the distance. v is the initial velocity. t is the amount of time. a is the acceleration. You know the values of everything in the equation except a. You can use algebra to get the value of a.

Don't forget to convert the units, too.