MDJH Posted June 24, 2010 Share Posted June 24, 2010 Momentum is a vector quantity, in the same direction as speed, and velocity is the magnitude and direction of said speed, with mass being the scalar coefficient by which velocity is multiplied to yield momentum, right? So let's say we're taking the derivative of momentum with respect to time (seeing as how that's what net force actually is) and mass of a particular object is transferring elsewhere... if we're analyzing the momentum of the object in particular, and both mass and velocity are changing at the same time, would the rate of change in momentum be: (dp/dt) = (dm/dt)*(dv/dt) OR (dp/dt) = m*(dv/dt) + v*(dm/dt) OR would it be something else because of the differing natures of the quantities involved? Link to comment Share on other sites More sharing options...
ajb Posted June 24, 2010 Share Posted June 24, 2010 Your second answer is correct, recall Leibniz's rule. Link to comment Share on other sites More sharing options...
MDJH Posted June 24, 2010 Author Share Posted June 24, 2010 Leibniz' rule? I'm not sure if I've heard of that one. Though if you're referring to the product rule, then yeah that's what I assumed applied in the 2nd case. I just wasn't sure if it worked differently when you had the product of a scalar and vector or something... Link to comment Share on other sites More sharing options...
ajb Posted June 25, 2010 Share Posted June 25, 2010 Leibniz' rule? I'm not sure if I've heard of that one. It is another name for the product rule. Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now