I have a question:
If an object is sliding on the earths surface:
and slows down due to kinetic friction, and only the object is
taken as the system, the kinetic force is taken as the external force.
But if both the aerth and the object are taken as a system, is the kinetic force an external or internal force?
Can the frictional force change the momentum of the two body system?
2007-06-21 20:32:33 · 3 answers · asked by Anonymous in Science & Mathematics ➔ Physics
Internal force.Yes
2007-06-21 20:35:51 · answer #1 · answered by sandeep 2 · 0⤊ 0⤋
If you take the system to be the Earth plus the object, then the only forces involved are between the Earth and the object. The forces are therefore internal forces, and cannot change the total momentum of the system. They only distribute it differently.
2007-06-22 03:38:11 · answer #2 · answered by lithiumdeuteride 7 · 1⤊ 0⤋
Newton's law applicable at earth.
Einstien law applicable to big astronomical bodies.
Richard feynman applicable to micro bodies.
You read first.
Regards
2007-06-22 03:52:17 · answer #3 · answered by Anonymous · 0⤊ 1⤋