And why do we care about momentum? We care about momentumīecause if there's no net external force on a system, the momentum of that What does momentum mean? The definition of momentum is
A rookie here.ĪP Center, High School Affiliated to RUC, Beijing, China
The sum of forces that are not exerted BY the system itself but are exerted ON the system.Īgain, thank you for asking. To reiterate, what to consider is merely the net third party force that does not belong to the original whole system you have been asked to consider. However, if we now expand a little bit and consider air resistance, will air resistance be a net force? Well, yes, since that is indeed a third party force that is not part of the system. They are simply regarded as "inner-forces" existed in the whole rocket-tank system. Will we consider the forces the tanks exert "net forces" to the whole system? Apparently no. My suggestion is that you decide whether there is a third party force exerted, say, by an experimenter.Ĭonsider the circumstance: A rocket and its additional tanks are fired up to the sky and after a while the tanks exert a repulsive force in the opposite direction of the rocket so they may separate with the rocket and fall. You may consider the phrase "net force" as "the external force", or "the force left over after subtracting all individual forces in a system", according to Giancoli AP Physics.
0 kommentar(er)
