Question

Specify two differences between internal and external forces

Answer 1

Internal forces are the forces acting amongst the particles of the system.
For example , in an atom , the intermolecular forces are the internal forces.External forces are the forces acting in the system from the sources that is outside the system. For example , consider another atom which has bonded with the given atom, this chemical bond is an external system.

Answer 2

Answer:

External forces are forces caused by external agent outside of the system. Internal forces are forces exchanged by the objects in the system. To determine what part should be considered external and internal, mechanical system should be clearly defined.