Force and Translational Dynamics unit test

A test on this unit alone, marked as a percentage and a letter grade — for the test your class is actually sitting, rather than for May. Answer everything, then submit once: seeing the answer to question 3 before attempting question 4 makes the final percentage meaningless.

Paper 1 Paper 2 Paper 3

Each paper is built from this unit’s 21 terms and is the same for everyone, so a teacher can assign “Unit 2, Paper 3” and every student sits the identical test. Multiple choice is marked objectively; the written sections you mark yourself against the model answer and rubric.

Suggested time 37 min 34 points0/17 attempted

Pulley constraints

Inclined plane analysis

Static and kinetic friction

Free-body diagram discipline

Velocity-dependent drag

Impulse from a variable force

Non-inertial frames

Orbits and Kepler's third law

Solving the terminal velocity differential equation

Gravitational potential energy sign

Gravitational field inside a sphere

Total energy of a circular orbit

Short answer 1. Define or explain: Newton's law of gravitation

3 pts

Short answer 2. Define or explain: Newton's second law in general form

3 pts

Short answer 3. Define or explain: Vertical circular motion condition

3 pts

Short answer 4. Define or explain: Systems with multiple bodies

3 pts

Free response

10 pts

A 0.20 kg sphere is released from rest and falls through air that exerts a drag force of magnitude bv opposite to the velocity, with b = 0.40 kg/s. Take g = 9.8 m/s² and take downward as positive.

Describe the free-body diagram and write Newton’s second law as a differential equation for v(t).

Determine the terminal speed.

Show that v(t) = v_t(1 − e^(−bt/m)) satisfies your differential equation and the initial condition, and identify the time constant.

Calculate the time at which the sphere reaches half its terminal speed.

Describe the shape of the v-versus-t and a-versus-t graphs, labeling asymptotes and intercepts, and state the acceleration at t = 0.