2- Relativity II

Question 1

2 properties of relativistic momentum

Answer 1

1) momentum is conserved in collisions
2) momentum approaches (mass)x(velocity) as (v/c) approaches zero.



Question 2

2 properties of relativistic energy

Answer 2

1. The total energy E of any isolated system is conserved.

2. E will approach the classical value when u/c approaches zero.

Question 3

distinction between conserved quantities and invariant quantities

Answer 3

The former have the same value before and after an interaction in a particular reference frame. The latter have the same value when measured by observers in different reference frames.

Question 4

the magnitude of the invariant energy-momentum four vector is the rest energy of the mass m

therefore…

Answer 4

…observers in all inertial frames will measure the same value for the rest energy of isolated systems and, since c is constant, the same value for the mass.

Question 5

the rest energy of a system of particles is not the sum of the rest energies of the individual particles if …

Answer 5

…they move relative to one another

Question 6

Principle of equivalence:

Answer 6

a homogeneous gravitational field is completely equivalent to a uniformly accelerated reference frame.