Unit 5: Torque and Rotational Dynamics
Physics 1 · Unit 5 · Paper 2

Torque and Rotational 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.

Each paper is built from this unit’s 38 terms and is the same for everyone, so a teacher can assign “Unit 5, Paper 2” 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 34 min 31 points0/17 attempted
1

Friction in rolling

2

Static equilibrium

3

Angular acceleration of a pulley with mass

4

Common moments of inertia

5

Two ways to compute a torque

6

Ranking the shape coefficients

7

Parallel axis theorem qualitatively

8

Rotational equilibrium

9

I depends on the axis, not just the object

10

Angular displacement, velocity, acceleration

11

Torque from weight on an extended object

12

Why mass distribution matters

Short answer 1. Define or explain: Why a door handle is far from the hinge

3 pts

Short answer 2. Define or explain: Choosing a pivot

3 pts

Short answer 3. Define or explain: Choosing the pivot to erase an unknown

3 pts

Short answer 4. Define or explain: Rolling without slipping

3 pts

Free response

7 pts

A uniform plank of mass 8.0 kg and length 4.0 m rests on two supports. Support A is at the left end and support B is 3.0 m from the left end. A block of mass 12.0 kg is placed 3.5 m from the left end. (a) Draw a free-body diagram for the plank, labeling all forces. (b) Calculate the force exerted by support B on the plank. (c) The block is slowly moved toward the right end. Determine the distance from the left end at which the plank will begin to tip, and explain the physical condition that defines tipping.

Draw a free-body diagram for the plank, labeling all forces.

Calculate the force exerted by support B on the plank.

The block is slowly moved toward the right end. Determine the distance from the left end at which the plank will begin to tip, and explain the physical condition that defines tipping.