Question #308
I sit on a rotating chair resting on a high-quality, very low-friction
bearing, so that when the chair rotates it creates very little torque
(let's say negligible for this experiment).
Holding a heavy dumbell in my right hand in front of my chest, I sit
firmly on the rotating chair, as seen in the photograph above. Rapidly in
succession I repeatedly extend my right arm to the right, rotate it
90o counterclockwise as viewed from above, to directly in
front of me, and return it to its original position at my chest. This
motion is shown in detail in the figure at the right above.
After doing this ten times I stop. What will be my situation at that
time?
- (a) I will be sitting motionless in the same position, but totally
exhausted.
- (b) I will have rotated clockwise as viewed from above and will be at
rest.
- (c) I will have rotated clockwise as viewed from above and will
continue rotating.
- (d) I will have rotated counterclockwise as viewed from above, and
will be at rest.
- (e) I will have rotated counterclockwise as viewed from above, and
will continue rotating.
- (f) I will have rotated about one complete turn and will be moving
clockwise.
- (g) I will have rotated about one complete turn and will be moving
counterclockwise.
Click here for Answer #Q308 after March 3, 2008.
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