...Rotation

This assignment is due before 9 AM Wednesday, Oct 18.

Please type LAST name:

Please type your LAST NAME and LAST FOUR SS# digits (eg: Smith3256):

I received no help from anyone on this assignment.

The following three questions refer to the material you were to read in preparation to the lesson. Questions one and two require you to write a three or four sentence response. Number three is a multiple choice question. Click in the appropriate circle.

You may change your mind as often as you wish. When you are satisfied with your responses, click the SUBMIT WARMUP button at the bottom of this page.




1.

What direction is the torque for a moment arm, r, which points east and an applied force, F, which point south? (I.e. you are trying to loosing a nut, the wrench points east from the nut, and you push south on the end of the wrench.  Lots of luck if you are pushing in the 'wrong' direction to loosen the nut!)



2.

The mass of the Earth is about 6x1024 kg and its radius is about 6x106 meters. Suppose you build a runway along the equator, line-up a million F-16's, bolt them down, and have them all fire their engines (eastward) simultaneously for 1/2 hour. Estimate the effect that would have on the rotational speed of the Earth. Assume the thrust of each plane's engines is 30,000 lbs = 133,000 Newtons.



3.

A human athlete spinning freely in mid-air cannot change his

angular speed

moment of inertia

rotational kinetic energy

all of the above conclusions are valid





Below is a space for your thoughts, including general comments about today's assignment. What was hard or confusing (or cool)? What would you like to spend extra time on in class? Do you see how this subject fits in with the others we have discussed?




You may change your mind as often as you wish. When you are satisfied with your responses click the SUBMIT button.

©2000 IUPUI, all rights reserved.