Using the postulate that the speed of light is the same in all inertial reference frames demonstrate that "moving clocks run slow" (time dilation) and that the measured length of a moving object in the direction of motion is shorter than that same length of the object's in an inertial frame in which the object is at rest.

An electron is ejected into a horizontal uniform e⃗ field at a parallel horizontal velocity of v0. assume the electron's initial position x0, initial velocity v0, time t, magnitude of electric field e, electron's mass m, and the magnitude of the electron's charge |e|. ignore the force that earth exerts on the electron. assume the e⃗ field is in the same direction as the initial velocity. part a define the equation for the electron's velocity. express your answer in terms of the variables v0, |e|, t, e, and m.