Question

The radius of the earth is 6378.1 km what is circumfrence of the earth in metres in standard form how many times can light encircle the earth per second

Answer 1

Answer:

Two things we need to remember:

Speed of light = c = 299,792,458 m / s

This means that the light in one second covers a distance of 299,792,458 m

And for a circle of radius R, the is:

C = 2*pi*R

where:

pi = 3.14

Then if the radius of the earth is 6,378.1 km, then the of the earth is:

C = 2*(3.14)*6,378.1 km = 40,054.468 km

And we know that 1 km = 1000m

Then the circumference of the earth is:

C = (40,054.468*1000) m = 40,054,468 m

Now we need to see how many times the light can encircle the earth per second. (we assume that the light can move in a circular path, this is not really accurate to the reality)

We know that in one second the light can cover a distance of:  299,792,458 m

And the circumference of the earth is: 40,054,468 m

The quotient between these two distances is the number of times that the light can encircle the earth:

N = (299,792,458 m)/(40,054,468 m)  = 7.5

So light could encircle the earth 7.5 times per second.