FE Civil · Chapter 6 · 4–6 questions

FE Civil Dynamics

This chapter tests kinematics, kinetics, energy methods, and momentum principles for particles and rigid bodies.

What the FE tests

The Dynamics skills NCEES checks

Kinematics

Kinematics describes motion without worrying about forces — how fast, how far, what path. Civil engineers use it to derive stopping sight distance on highways, predict projectile trajectories for debris analysis, and calculate the motion of rotating machinery components.

Kinetics & Energy

Kinetics connects forces to the motion they cause. Civil engineers use Newton's second law to compute dynamic forces from earthquake ground acceleration on a building, impact forces on bridge barriers, and work-energy methods to size pump motors, design guardrails for crash energy absorption, and calculate power requirements for construction equipment.

Momentum & Vibrations

Impulse-momentum methods handle short-duration forces like vehicle impacts on bridge piers and water jets on turbine blades. Vibration analysis ensures pedestrian bridges don't resonate with footfalls, buildings don't amplify earthquake motion, and machine foundations don't vibrate excessively.

Reference

Key Dynamics formulas

$v = v_0 + at$ Constant AccelerationFE Handbook p. 104
$s = s_0 + v_0 t + \frac{1}{2}at^2$ DisplacementFE Handbook p. 104
$v^2 = v_0^2 + 2a(s - s_0)$ Velocity-PositionFE Handbook p. 104
$\sum F = ma$ Newton's Second LawFE Handbook p. 105
$T_1 + V_1 = T_2 + V_2$ Conservation of EnergyFE Handbook p. 106
$m_1 v_1 + m_2 v_2 = m_1 v_1' + m_2 v_2'$ Conservation of MomentumFE Handbook p. 108
$\omega_n = \sqrt{k/m}$ Natural FrequencyFE Handbook p. 112

Try it

Sample Dynamics problems

Q1A truck accelerates uniformly from $10\,\text{m/s}$ to $30\,\text{m/s}$ over a distance of $200\,\text{m}$ . What is the acceleration?

$2.0\,\text{m/s}^2$

Explain it simply

You have initial velocity, final velocity, and distance — but no time. That combination screams v-squared equation. Plug in and solve for a. Choice A comes from dividing the velocity difference by the distance (20/200). Choice C comes from squaring velocity difference divided by distance incorrectly.

Q2A projectile is launched from ground level at $40\,\text{m/s}$ at $45\degree$ above the horizontal. What is the total horizontal range? Use $g = 9.81\,\text{m/s}^2$ .

$163.1\,\text{m}$

Explain it simply

For range, you can either use the range formula $R = v_0^2 \sin(2\theta) / g$ , or work it from first principles: find time of flight from the vertical equation, then multiply by horizontal velocity. At 45 degrees, $\sin(90°) = 1$ , so $R = v_0^2 / g$ . Choice B comes from using $v_0 \sin 45°$ instead of $v_0^2$ . Choice D comes from doubling the correct answer — maybe computing total distance incorrectly.

2 of 1,126 problems across all 15 chapters — the full bank, lessons, mastery tracking, and timed exam simulation live inside the app.

Avoid these

Common Dynamics mistakes

Using kinematic equations when acceleration is NOT constant — they only work for uniform acceleration.
Forgetting to include all forces (gravity, friction, normals) in ΣF = ma — draw the FBD first.
Mixing up elastic and inelastic collisions — kinetic energy is only conserved in elastic collisions.
Not converting angular units — ω must be in rad/s, not rpm, for most formulas.
Confusing velocity and speed in projectile motion — velocity has direction.

FAQ

FE Civil Dynamics: common questions

How many FE Civil Dynamics questions are on the exam?

NCEES includes roughly 4–6 Dynamics questions on the computer-based FE Civil exam, which has 110 questions total over about six hours.

What Dynamics topics does the FE Civil exam cover?

The FE Civil exam tests Dynamics across: Kinematics, Kinetics & Energy, Momentum & Vibrations.

Is FE Civil Dynamics hard?

Dynamics is very learnable for the FE. It rewards recognizing a handful of standard problem types and applying the right FE Reference Handbook formula — not deep theory. Practicing past-style problems is the fastest way to master it.

Where can I find free FE Civil Dynamics practice problems?

FE for Raccoons has free Dynamics lessons and practice problems with step-by-step explanations — part of a 1,126-problem bank covering all 15 FE Civil topics, free at fe4raccoons.com.

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Bite-sized lessons, one-problem-at-a-time practice with instant feedback, and progress that adds up every day you study — built for the FE Civil exam.

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