PHYS 3310 Module 2 Activity 2

Relativistic Momentum

Practice 2.2.1
Particle A has half the mass and twice the speed of particle B. Is pA less than, greater than, or equal to pB
A. pA < pB
B. pA > pB
C. pA = pB
Check your answer: B. pA > pB
Practice 2.2.2
A proton was measured to have momentum 8.00 × 10-20 kg·m/s. What is its speed?
A. 0.079c
B. 0.157c
C. 0.471c
D. 0.314c
Check your answer: B. 0.157c

As a particle speeds up and approaches c, what happens to the particle’s momentum? Sketch a graph of the particle’s momentum versus its speed.