At what speed, as a fraction of c, does a moving clock tick at four fifth the rate of an identical clock at rest?

The seed as a fraction of the speed of light is

Solution:

As per the question:

Suppose, be the rate of an identical clock between two time intervals.

For a moving clock, moving with velocity 'v', at the clock tick of four-fifth:

t =

Now,

Using the relation of time dilation, from Einstein's relation:

Squaring both sides:

car stops. he keeps going = he has inertia

.) the observation by semmelweis that more mothers died of childbed fever when their doctors also worked in the morgue