Momentum

Now we move on to momentum. This is basically the product of an objects mass and velocity. In other words, mass times velocity. Momentum is usually indicated by the letter p , and mass by m . Thus, the following should be pretty self-explanatory:

 p = m * v 

This means that something with a small mass and high velocity could have a similar momentum to something with a large mass and low velocity. The aforementioned large truck moving at a mere 20 miles an hour could easily kill you. A bullet, on the other hand, has a relatively tiny mass but a much higher velocity, and its just as deadly .

Because velocity is a vector (direction and magnitude), that means momentum must also be a vector. The direction of the momentum vector is the same as the direction of the velocity vector. Thus, to fully describe momentum, you say something like this (where m/s is meters per second):

 5 kg * 20 m/s at 23 degrees 

Pretty complex, eh? Now you know why Ive waited until now to bring it up.