Chronology | Current Month | Current Thread | Current Date |
[Year List] [Month List (current year)] | [Date Index] [Thread Index] | [Thread Prev] [Thread Next] | [Date Prev] [Date Next] |
Gary Turner wrote:
. . .>static friction only here and the end result is that the force is
Now, is that sufficient? Is the car going to move? I have relied on
between
the engine and tires.
Analyses of the internal forces between (or among) the internal parts of a
system (the car or the skater) will illuminate the mechanism whereby the
increased kinetic energy of certain system parts (tires; skater's arm) is
generated. This kinetic energy is internal to the system and will not
directly change the system (CM) momentum - as happens on ice, where much
KE is generated but no CM acceleration. These moving parts must then be
used (through mechanisms of friction, rigidity, etc) to elicit a force
from an external object in order to produce a momentum exchange between
the system and the external world.
Bob Sciamanda (W3NLV)
Physics, Edinboro Univ of PA (em)
trebor@velocity.net
http://www.velocity.net/~trebor