Physics quiz question: distance of a light "hellasecond"

Physics 205A Quiz 1, fall semester 2011
Cuesta College, San Luis Obispo, CA

Given that the speed of light in vacuum is 3.00×10⁸ m/s, how many meters would light travel in 1 Hs (1 "hellasecond" = 10²⁷ s)?
(A) 3.33×10³⁶ m.
(B) 3.00×10^–19 m.
(C) 3.33×10¹⁸ m.
(D) 3.00×10³⁵ m.

Correct answer (highlight to unhide): (D)

The speed of light in vacuum is c = 3.00×10⁸ m/s, and the relation between speed, distance, and elapsed time is:

c = ∆x/∆t,

such that solving for ∆x gives:

∆x = c⋅∆t = (3.00×10⁸ m/s)⋅(1e×10²⁷ s) = 3.00×10³⁵ m.

(Response (A) is 1/(c⋅∆t); response (B) is c/∆t, and response (C) is ∆t/c.)

Sections 70854, 70855
Exam code: quiz01unI7
(A) : 3 students
(B) : 10 students
(C) : 1 student
(D) : 42 students

Success level: 74%
Discrimination index (Aubrecht & Aubrecht, 1983): 0.33

Compare to results of a similar "hella-" problem asked of second-semester college physics students (fall semester 2010).