Work, Energy, and Power
Momentum and Impulse
|The principles of Momentum & Impulse are a direct consequence of Newton's Laws, providing a useful framework to analyze the motion of a system containing many particles. Another way of expressing Newton's 2nd Law, for example, instead of 'force equals mass times acceleration' is to say "force equals the time rate of change of momentum". Furthermore, the proposition of Newton's 3rd Law, that "every force is accompanied by an equal and opposite force" leads naturally to the Law of Conservation of Momentum. |
Momentum & Impulse is a favorite on the exam for straightforward, traditional physics problems. Furthermore, the Law of Conservation of Momentum is frequently used as a basis for questions of a conceptual nature (Conservation principles naturally lend themselves to conceptually oriented multiple choice questions). The majority of MCATs contain a passage in which students must demonstrate the ability to fluently apply concepts from Dynamics and Work & Energy. Dynamics includes the concepts of both Newton's Laws and Momentum & Impulse. If you get stuck on a problem you have been conceptualizing in terms of force acting through a distance (work), it may help to step back and think in terms of force acting through a time (impulse). In other words, it is helpful to practice framing mechanical problems in terms of both Dynamics and Work & Energy as a matter of habit.