일반물리학 2 — Relativity: Problem 17

17 As you read this page (on paper or monitor screen), a cosmic ray proton passes along the left–right width of the page with relative speed \(v\) and a total energy of 23.16 nJ. According to your measurements, that left–right width is 21.0 cm. (a) What is the width according to the proton’s reference frame? How much time did the passage take according to (b) your frame and (c) the proton’s frame?