options. First, make up a reasonable answer for part (a), and then use that answer for part (b). Or, set
some variable equal to the answer from part (a) (write a note saying something like, “Let v be the
velocity found in part (a)”). Then, solve part (b) in terms of that variable. Both of these methods should
allow you to get partial or even full credit on part (b).
• If you make a mistake, cross it out. If your work is messy, circle your answer so that it’s easy to find.
Basically, make sure the AP graders know what you want them to grade and what you want them to
ignore.
• If you’re stuck on a free-response question, try another one. Question #3 might be easier for you than
question #1. Get the easy points first, and then only try to get the harder points if you have time left
over.
• Always remember to use units where appropriate.
• It may be helpful to include a drawing or a graph in your answer to a question, but make sure to label
your drawings or graphs so that they’re easy to understand.
• No free-response question should take you more than about 15 minutes to solve. They’re not designed
to be outrageously difficult, so if your answer to a free-response problem is outrageously complicated,
you should look for a new way to solve the problem, or just skip it and move on.
Lab Questions
It is all well and good to be able to solve problems and calculate quantities using the principles and
equations you’ve learned. However, the true test of any physics theory is whether or not it WORKS.
The AP development committee is sending a message to students that laboratory work is an important
aspect of physics. To truly understand physics, you must be able to design and analyze experiments. Thus,
each free-response section will contain at least one question that involves experiment design and
analysis .
Here’s an example:
In the laboratory, you are given a metal block, about the size of a brick. You are also given a 2.0-m-long
wooden plank with a pulley attached to one end. Your goal is to determine experimentally thecoefficient of kinetic friction, μ (^) k , between the metal block and the wooden plank.
(a) From the list below, select the additional equipment you will need to do your experiment by
checking the line to the left of each item. Indicate if you intend to use more than one of an item.
(b) Draw a labeled diagram showing how the plank, the metal block, and the additional equipment you
selected will be used to measure μ (^) k.
(c) Briefly outline the procedure you will use, being explicit about what measurements you need to
make and how these measurements will be used to determine μ (^) k.
To answer a lab question, just follow these steps: