I have noticed just in the past couple of years that I get a red splotchy rash on my neck when I drink beer. I thought it might be an allergic reaction, but it doesn't happen all of the time when I drink beer. I have tried switching to a different kind of beer, but I still have random outbreaks of this rash. Answer.
So, if two objects have the same energy $E_k$, they only have the same momentum if they also have the same mass. Since the bull has a much larger mass than the bullet, it must therefore have a much larger momentum than the bullet to arrive at the same kinetic energy. Force is change of momentum with time, $F = \dot p$.
In relative physics, mass has two components: the classical mass, described above, also known as rest mass (or invariant mass), and relativistic mass. A body's rest mass remains constant, and its relativistic mass is zero when the the body is not moving (i.e., at rest).