Department of Energy Argonne National Laboratory Office of Science NEWTON's Homepage NEWTON's Homepage
NEWTON, Ask A Scientist!
NEWTON Home Page NEWTON Teachers Visit Our Archives Ask A Question How To Ask A Question Question of the Week Our Expert Scientists Volunteer at NEWTON! Frequently Asked Questions Referencing NEWTON About NEWTON About Ask A Scientist Education At Argonne Earth's Rotational Speed
Name: Renee
Status: Other
Age: 30s
Location: N/A
Country: N/A
Date: N/A 


Question:
I can understand that the poles arent moving as far as the equator is but it is still moving. Since the earth is one mass how can a different space move faster than another? So what do you mean the equator is moving faster than another part?



Replies:
Renee -

The problem with analyzing motion is the need for a point of reference - a place we assume is standing still. I am standing still compared to the chair I am sitting on, yet I am moving rather fast compared to the center of the earth. What might help with your question is if you think of looking straight down on the north pole and considering the north pole as your frame of reference. The equator would appear to move a much greater distance than the north pole (which seems appears to be standing still).

Which person on the merry-go-round moves faster? If you assume the earth is standing still, the person on the outside is moving faster. But, it is all relative. Hope that helps.

Larry Krengel


Assuming that the Earth makes one turn every twenty four hours, and the Earth if wider at the equator, you have to cover more distance to spin past a point. Thus to cover that distance, you have to move faster at the equator than at the pole.

Glenn


Once per day, the earth rotates about its axis. In each rotation, a point on the equator will move farther than a point on the axis. Since it moves farther in the same amount of time, it MUST be moving faster.

As I understand it, your objection is that we're claiming that two points can move at different speeds and still stay the same distance from each other. Clearly, this can't happen if both points are constrained to be in a line. However, when one object revolves around another (for example), the distance does not have to change. Just because the two objects move at different speeds, they aren't necessarily moving away from each other.

Richard E. Barrans Jr., Ph.D.
Assistant Director, PG Research Foundation
Darien, IL USA



Click here to return to the Environmental and Earth Science Archives

NEWTON is an electronic community for Science, Math, and Computer Science K-12 Educators, sponsored and operated by Argonne National Laboratory's Educational Programs, Andrew Skipor, Ph.D., Head of Educational Programs.

For assistance with NEWTON contact a System Operator (help@newton.dep.anl.gov), or at Argonne's Educational Programs

NEWTON AND ASK A SCIENTIST
Educational Programs
Building 360
9700 S. Cass Ave.
Argonne, Illinois
60439-4845, USA
Update: June 2012
Weclome To Newton

Argonne National Laboratory