🚀 go-pugleaf

RetroBBS NetNews Server

Inspired by RockSolid Light RIP Retro Guy

Thread View: bit.listserv.physhare
1 messages
1 total messages Started by John Mallinckrodt Tue, 16 May 1995 00:00
Re: Forces
#98
Author: John Mallinckrodt
Date: Tue, 16 May 1995 00:00
31 lines
1762 bytes
David,  Here is a brief answer to your question.
                                                              _
Tap on a long thin stick as shown at right with a force F    | |
for a (short) time t.  Assume the stick is initially         | |
motionless.  The change in the momentum equals the impulse   | |
                                                             | |
    ma t = F t                                            ___|.|
    mv = Ft       (where a and v are those of the CM)      | | |
                                                           x | |
The change in the intrinsic angular momentum (i.e.,        | | |
that about the CM) is equal to the torque about the      F-->| |
CM times t.                                                  |_|

 (rot. inertia about CM) (ang. acc. about CM) t = (Torque about CM) t
 (ml^2/12) w = Fxt

(where w is the angular velocity of the resulting rotation about
the CM.  Note that if the torque is calculated about points other
than the CM you must also deal with the change in the "orbital"
angular momentum--i.e., that due to the motion of the CM.)

Eliminate Ft from the above.

   w/v = 12x/l^2

So the larger x is, the larger is the ratio of w to v.  Makes
sense.

John Mallinckrodt
Cal Poly Pomona
ajmallinckro@csupomona.edu
Thread Navigation

This is a paginated view of messages in the thread with full content displayed inline.

Messages are displayed in chronological order, with the original post highlighted in green.

Use pagination controls to navigate through all messages in large threads.

Back to All Threads