Physics quiz question: Boltzmann constant

Physics 205A Quiz 1, fall semester 2014
Cuesta College, San Luis Obispo, CA

Cf. Giambattista/Richardson/Richardson, Physics, 2/e, Problems 1.37, 1.39

The Planck temperature TP (measured in units of K) is given[*] by the expression:

TP = mP·c2/kB.

Planck mass mP is measured in units of kg, and the speed of light c is measured in units of m·s–1. The units for the Boltzmann constant kB are:
(A) kg–1·m–2·s2·K.
(B) kg–1·m2·s–2·K.
(C) kg·m–2·s2·K–1.
(D) kg·m2·s–2·K–1.

[*] wki.pe/Planck_temperature.

Correct answer (highlight to unhide): (D)

Replacing the quantities in the equation with their kg, m, s and K units, except for the Boltzmann constant kB:

K = kg·(m/s)2/kB,

kB = kg·m2/(s2·K).

Sections 70854, 70855, 73320
Exam code: quiz01w34K
(A) : 5 students
(B) : 6 students
(C) : 1 student
(D) : 62 students

Success level: 84%
Discrimination index (Aubrecht & Aubrecht, 1983): 0.37

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