Original question written by FE Exam AI Prep from the public FE Civil exam specification. Before release, a solver model re-derived the answer twice from the question alone, without its answer key, and a critic model checked the result, and the arithmetic was re-run as an executable calculation. No licensed engineer reviews these questions. It is not an NCEES question and does not come from any NCEES practice exam. FE Exam AI Prep is an independent study tool and is not affiliated with, endorsed by, or sponsored by NCEES.
MEDIUMs = ((v_i + v_f)/2)t
Average Velocity and Constant Acceleration: FE Civil practice problem 4
For the Iron Ridge concrete-lined channel, a hydrology reviewer preparing a design validation memo tracks equipment accelerating uniformly from 9 m/s to 20 m/s over 6 s. What distance is traveled?
- A58.0 m
- B87.0 m
- C73.7 m
- D81.3 m
Show the answer and worked solution
Answer: B — 87.0 m
Worked solution
- Step 1. Find average velocity
v_avg = (v_i + v_f)/2
v_avg = (9 + 20)/2 = 14.5 m/s
- Step 2. Multiply by time
s = v_avg t
s = 14.5(6) = 87 m
Why the other choices are wrong
- Choice A
- This number runs about 33% under the verified total and does not correspond to one identifiable substitution mistake in the average-velocity distance method; the direct computation is v_avg = (9 + 20)/2 = 14.5 m/s, then s = 14.5 * 6 = 87 m.
- Choice C
- This value lands around 18% above the checked total, and no single obvious substitution in the average-velocity distance method reproduces it; the stated numbers work out directly to v_avg = (9 + 20)/2 = 14.5 m/s, then s = 14.5 * 6 = 87 m.
- Choice D
- This total sits roughly 7% under the true result, and no single unit slip, sign flip, or misapplied factor in the average-velocity distance method reproduces it cleanly; the reliable path computes v_avg = (9 + 20)/2 = 14.5 m/s, then s = 14.5 * 6 = 87 m.