Unit 2: Force and Translational Dynamics
Physics 1 · Unit 2 · Paper 1

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 1Paper 2Paper 3
Each paper is built from this unit’s 52 terms and is the same for everyone, so a teacher can assign “Unit 2, Paper 1” 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
1

Systems and internal forces

2

Centripetal force is not a new force

3

Weight vs mass

4

Equilibrium

5

Vertical circular motion

6

The massless string assumption

7

Centripetal acceleration

8

Direction of friction

9

Inertial mass vs gravitational mass

10

Free-body diagram

11

A free-body diagram has no ma arrow

12

Tension

Short answer 1. Define or explain: Apparent weight

3 pts

Short answer 2. Define or explain: Connected objects

3 pts

Short answer 3. Define or explain: Newton's law of gravitation

3 pts

Short answer 4. Define or explain: The coefficient of friction has no units

3 pts

Free response

10 pts

Students are asked to determine the coefficient of kinetic friction between a wooden block and a horizontal laboratory bench. They have a spring scale, a set of known masses, and a meterstick. The students place masses on top of the block and pull it horizontally with the spring scale so that it slides at constant velocity, recording the scale reading F for each total mass m. m (kg) 0.50 1.00 1.50 2.00 2.50 F (N) 1.7 3.4 5.2 6.8 8.6

A(i). Explain why the students pull the block at constant velocity rather than accelerating it. A(ii). Describe one step that would reduce experimental uncertainty in the force measurements.

B(i). Indicate what quantities should be plotted on the horizontal and vertical axes to produce a straight line that can be used to determine the coefficient of kinetic friction. B(ii). Describe how the coefficient is related to a feature of that graph.

C(i). Describe the axis labels, with units, and the positions of the plotted points. C(ii). Describe the best-fit line.

D. Using the best-fit line described in part C, calculate an experimental value for the coefficient of kinetic friction.