Suppose a particle's four-momentum vector has components $\left[p_{t}, p_{x}, p_{y}, p_{z}\right]=[5 \mathrm{~kg}, 3 \mathrm{~kg}, 0,0]$. What is this particle's mass?
A) $5 \mathrm{~kg}$
B) $8 \mathrm{~kg}$
C) $4 \mathrm{~kg}$
D) $3 \mathrm{~kg}$
E) $\sqrt{34} \mathrm{~kg}$
F) Other (specify)

Question

Quizplus · Accepted Answer

Note that $m^{2}=p_{t}^{2}-p_{x}^{2}-p_{y}^{2}-p_{z}^{2}=(5.0 \mathrm{~kg})^{2}-(3.0 \mathrm{~kg})^{2}-0-0=(25-9) \mathrm{kg}^{2}=[4.0 \mathrm{~kg}]^{2}$.

Suppose a Particle's Four-Momentum Vector Has Components [pt,px,py,pz]=[5 kg,3 kg,0,0]\left[p_{t}, p_{x}, p_{y}, p_{z}\right]=[5 \mathrm{~kg}, 3 \mathrm{~kg}, 0,0][pt​,px​,py​,pz​]=[5 kg,3 kg,0,0]

Suppose a Particle's Four-Momentum Vector Has Components $\left[p_{t}, p_{x}, p_{y}, p_{z}\right]=[5 \mathrm{~kg}, 3 \mathrm{~kg}, 0,0]$