Dynamics Tutoring

• Choosing between force, energy, and momentum. Newton's second law, work–energy, and impulse–momentum will all eventually give the same answer, but only one of them gets there in the time an exam allows. The question the problem is really asking — is this about a position, a speed, or an interval of time? — is the whole decision, and it is almost never stated.
• Kinematics and kinetics run together. Kinematics describes motion, kinetics explains why. Problems that mix them get solved with one set of tools and the other set's assumptions still attached.
• Picking the wrong coordinate system. Cartesian, normal–tangential and polar are not interchangeable in practice. A problem that is three lines in normal–tangential coordinates can be a page of trigonometry in Cartesian.
• Constraint equations nobody wrote down. Rolling without slipping, inextensible cables, pulleys — the missing equation is a physical statement about how the parts are attached, and it is the one most likely to be left out.
• Rigid-body rotation. Moment of inertia about the wrong axis, the parallel-axis theorem applied in the wrong direction, and mass centres treated as though they were pivots.
• Relative motion. Velocity and acceleration measured in a frame that is itself accelerating, where the extra terms are real physics rather than algebra.

Method selection is the first question, every time. Before anything is calculated we decide whether this is a force problem, an energy problem, or a momentum problem, and I make you say why. Getting this right turns most problems into short ones; getting it wrong makes them unfinishable in exam time.

The diagram still decides the answer. The free-body diagram habit from Statics does not stop applying — it gains a kinetic diagram beside it. If a student arrives shaky on free-body diagrams, that is what we fix first, because nothing downstream works without it.

Coordinates are chosen deliberately, not by default. We look at the path before choosing the frame. Choosing normal–tangential coordinates because the motion is along a curve is a decision worth making explicitly.

Constraints are written as equations before they are needed. If a cable is inextensible or a wheel rolls without slipping, that is an equation. Writing it down early is the difference between a determinate problem and a stuck one.

Answers get checked physically. A negative acceleration, an energy that increased, a momentum that did not conserve when it should have — each of these means something specific, and reading them catches errors no algebra check will.

Preparation is built around your course, not a stock problem set. The ASVAB is the one subject I keep a prebuilt curriculum for, because that exam has a single published blueprint that is the same for every student. University coursework is not like that — notation, sequence and what the exam emphasises vary by instructor — so for Dynamics I prepare against your own material instead. Send the topics, the assignment, the review sheet or the exam coverage ahead of time and I will have work ready for what you are actually being graded on.