top of page
Writer's picturekeshprad

PhysicsBowl 2018 Q49


49) This question asks us to find the mass of a particle with a given momentum and energy. First, we can set up the relativistic energy and momentum for this problem.

Where m is mass, v is velocity, γ is the Lorentz factor, and c is the speed of light

After this, we want to simplify this equation. Some people might try to expand the Lorentz factor; this would leave them with two equations and two unknowns: velocity and mass. Although this could work, it will make the problem unnecessarily hard, and there is a much simpler solution.


We can divide the equations, therefore eliminating m and γ and alowing us to solve for velocity. After solving for velocity, we would then plug this back into the original equation to solve for mass.


Now that we have a plan to solve this problem, let's start by trying to divide the two equations.

Where m is mass, v is velocity, γ is the Lorentz factor, and c is the speed of light

Finally, we can use velocity to solve for the Lorentz factor, then use either of our initial equations to solve for mass.

Where γ is the Lorentz factor, v is velocity, c is the speed of light, and m is mass

Comments


bottom of page