Question

If the radius of the earth’s orbit around the sun is 150 million kilometers, what is the speed of the earth in its orbit in kilometers per hour ?

Answer 1

I tried this:

Explanation:

We can use some relationships from Kinematics (rotational and linear):

1) linear (`v`) and angular (`omega`) velocity are related as:

`v=omegar`

2) angular velocity is the circumference described in time or:

`omega=(2pi)/T`

where `T` is the Period or time for an entire (`2pi` radians) orbit.

In our case: `T=1"year"=365*24=8760h`

so `omega=(2*3.14)/8760 rad \/h`

so that:

`v=omega r=(2*3.14)/8760*150xx10^6=1.07xx10^5 km \/h`