Phys 201 1nd Edition Lecture 16 Outline of Last Lecture I. Power and momentum Outline of Current Lecture II. MomentumIII. Momentum of a SystemIV. Conservation of momentumV. Collisions in a systemCurrent LectureMomentum:Objects can have different masses but the same momentum(p). Naturally this means that if you have a bigger mass, your velocity will be smaller to adjust. This means that heavier objects will always have smaller kinetic energy, even if the momentum is the same.Momentum of a system:Each object (A and B) has velocity and mass, so obviously we can calculate momentum for each. However, if we think of these two objects as a system we can add their properties together to calculate the momentum of the two objects. We can also look at the external and internal forces of a system. The internal force refers to the force that the two objects have on one another. Ptot=pA + PbFnet=FextA + FextB + internalsFnet=[(ΔpA/Δt)+(ΔpB/Δt)]=Δptot/ΔtConservation of Momentum:What if the external energy is equal to 0(0=Δptot/t). This means that there is no change in in the momentum over time, meaning that the final and initial momentums are the same. This is conservative momentum. For the momentum of a system, this means that if two objects collide with one another, themomentum lost by one object will be equal to the momentum gained by the other object. Collisions: These notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.As I said, when two objects collide, one object gains momentum and the other object loses momentum, and these amounts are equal to one another. This also means that, without the effects of external forces the sum of the momentum of the two objects before the collision is equal to the sum of the momentum of the two objects after the collision. If we express this as an equation, it looks like; m1V1+m2V2=m1V1’+m2V2’The superscript (‘) indicates that we are looking at the velocities after the collision, when the objects are moving away from each other. The velocities without a superscript indicate that these velocities are before the collision, when the objects are moving towards each other. For this equation, velocity depends a lot on the mass of an object. The heavier an object it, the slower it will be moving after a
View Full Document