Question
(a) Calculate the speed of a $1.00 \textrm{ }\mu\textrm{g}$ particle of dust that has the same momentum as a proton moving at $0.999c$. (b) What does the small speed tell us about the mass of a proton compared to even a tiny amount of macroscopic matter?
1. $1.12 \times 10^{-8} \textrm{ m/s}$
2. This small velocity of the dust particle says the proton has a very significantly smaller mass than the dust.
Solution Video