Unit 5: Torque and Rotational Dynamics
Physics 1 · Unit 5 · Paper 3

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.

Paper 1Paper 2Paper 3
Each paper is built from this unit’s 38 terms and is the same for everyone, so a teacher can assign “Unit 5, 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 34 min 31 points0/17 attempted
1

A force through the pivot makes no torque

2

I depends on the axis, not just the object

3

Rotational kinematic equations

4

Moment of inertia

5

Static equilibrium of a beam

6

Parallel axis theorem qualitatively

7

Sign of torque

8

Why rotational inertia squares the distance

9

Angular kinematics

10

Ranking the shape coefficients

11

Rotational equilibrium

12

Two ways to compute a torque

Short answer 1. Define or explain: Choosing the pivot to erase an unknown

3 pts

Short answer 2. Define or explain: What provides the torque in rolling

3 pts

Short answer 3. Define or explain: Center of gravity and tipping

3 pts

Short answer 4. Define or explain: Choosing a pivot

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.