Every 24 hours, Earth makes a full rotation around its axis. Earth's speed of rotation at the equator is 1,670 km per hour. What is the circumference of Earth's equator?

(Hint: Earth's circumference at the equator is equal to the distance that Earth rotates around the equator).

Guest Apr 7, 2019

#1**-4 **

Well if the circumfrence is equal to a complete rotaion than all that is required is to melitply 1,670 x 24 like this.

\(1,670\times 24 = product\)

\(product = circumfrance\)

Do correct me though if I miss interpeted the problem.

-HL

HiylinLink Apr 7, 2019

#2**+1 **

Sometimes it helps to cancel units. You can cancel units the same as you cancel numbers.

Example: 1670 km/hour x 24 hour/1 =

I just put hour over 1 to make it obvious that hour is a numerator in that term.

Cancel the hour in the denominator of km/hour and the hour in the numerator: km/~~hour~~ x ~~hour~~/1 = km/1 or simply km

And it's just arithmetic to multiply the numbers 1670 x 24

That's going to come to **approximately** 40,000 because 24 is almost (100 x 1/4) and (1/4 x 1670) is close to 400

You should multiply them on out formally and get the exact answer.

.

Guest Apr 8, 2019