BYU Physics 121 Chapter 1 Conceptual
Questions with complete solution 2025
Suppose that a represents an acceleration, v represents a velocity, x
represents a distance, and t represents a time. Which of the equations shown
below is in error, as shown by dimensional analysis? (See Table 1.5 in your
book.) - correct answer ✔b) x = vt + at/2
Feedback on part b: Correct answer. The equation was
[x] = L,
[v] = L/T,
[a] = L/T2,
so L = L/T * T + L/T2 * T = L + L/T and this is dimensionally incorrect. The
second term is not a length, but rather a velocity. Note that the factor of 2 in
the denominator is dimensionless and doesn't enter the calculation of
dimensional correctness.
To convert the speed of 14.5 furlongs/fortnight to meters/second, you should
multiply which of the following conversion factors times 14.5
furlongs/fortnight?
I. (1 fortnight/14 days) IV. (14 days/1 fortnight)
II. (1 furlong/201.168 m) V. (201.168 m/1 furlong)
III. (1 day/86400 seconds) VI. (86400 seconds/1 day) - correct answer ✔I, III,
V
The number of standard helium balloons that can be put into a minivan is
closest to - correct answer ✔c. 200
Questions with complete solution 2025
Suppose that a represents an acceleration, v represents a velocity, x
represents a distance, and t represents a time. Which of the equations shown
below is in error, as shown by dimensional analysis? (See Table 1.5 in your
book.) - correct answer ✔b) x = vt + at/2
Feedback on part b: Correct answer. The equation was
[x] = L,
[v] = L/T,
[a] = L/T2,
so L = L/T * T + L/T2 * T = L + L/T and this is dimensionally incorrect. The
second term is not a length, but rather a velocity. Note that the factor of 2 in
the denominator is dimensionless and doesn't enter the calculation of
dimensional correctness.
To convert the speed of 14.5 furlongs/fortnight to meters/second, you should
multiply which of the following conversion factors times 14.5
furlongs/fortnight?
I. (1 fortnight/14 days) IV. (14 days/1 fortnight)
II. (1 furlong/201.168 m) V. (201.168 m/1 furlong)
III. (1 day/86400 seconds) VI. (86400 seconds/1 day) - correct answer ✔I, III,
V
The number of standard helium balloons that can be put into a minivan is
closest to - correct answer ✔c. 200
