2 How to Approach Free-Response Questions

You should show the graders what you're thinking on the free-response section.

If your method is correct, you can still earn points if you make a mistake and carry an incorrect result to a later part of the question.

The graders can't give you credit for work you can't read or follow.
Units should be included in your final answers.

The ability to demonstrate an understanding of physics principles is required by both terms.

An argument is supported by evidence.

Statements of physical principles, equations, calculations, data, graphs, and diagrams are examples of evidence.

In some cases, the equation used to support justifications and explanations may refer to fundamental ideas or relations in physics, such as Coulomb's Law.
In some cases, the explanation may include analyzing the behavior of an equation for large or small values of a variable.

The final answer is usually obtained using mathematics.

Showing work leads to answers is a good idea, as you can earn partial credit in the case of an incorrect answer.
Strict rules regarding significant digits are not usually applied to the scoring of numerical answers.
In some cases, answers with too many digits may be punished.
Two to four significant digits are acceptable.
When rounding makes a difference, there are exceptions to the guidelines.

Specific data is not required in a sketch.

Plot means to draw the data points given in the problem on the grid provided, either using the given scale or indicating the scale and units when none are provided.

The components that are included in the diagram will be scored the same way as the incorrect or extraneous forces.

If you need to draw anything other than what you have shown in part [x] to assist in your solutions, use the space below.
This will allow you to make a diagram showing components that are appropriate to the problem.

An orderly sequence of statements is what you are expected to provide.

Section II is worth 50 percent of your grade on the exam.

There are five free-response questions in this section.

You're given 90 minutes for this section.

Readers grade your answers to the free-response questions.

AP physics 1 is about communication.
Write your answers in sentences.
Getting the correct numerical answer is not enough.

The space provided for each question should not be filled up.

The space is usually more than enough.
Some students write in big letters while others make mistakes, and the people who design the tests realize that.
Don't worry about the extra space if you have a complete solution.
Writing more won't earn you credit.
Many students go too far and make a mistake after they've already written the right answer.

Some questions might have more than one part.

Don't give up on the question if one part is giving you trouble, try to answer them all.
If the answer to part (b) depends on the answer to part (a), but you think you got the answer to part (a) wrong, you should still go ahead and do part (b) as required.

Chances are that the grader won't mark you wrong again unless it's obvious that you made a mistake.

Use common sense when answering questions.

Some students answered 70 pounds when asked to calculate the weight of a newborn baby on the Moon.
It should have been obvious that the answer was off.

This is a mistake that should be easy to fix.

From the answer, some mistakes may not be obvious.
Simple, easily recognizable errors will be considered very important by the grader.

You'll be doing calculations by hand in your free-response questions.

Don't forget to include units or dimensions in your final answer.

Try to think about what the grader is expecting when you answer a question.

The examples give you an idea of how the answers should be phrased.
There are two aspects to the scoring of freeresponse answers, one of which is showing a comprehensive knowledge of physics.
The responses should be written in complete sentences.
You don't have to show all the steps of a calculation, but you have to explain how you got your answer.

If he had eight hours to chop down a tree, Lincoln would spend six of them sharpening his axe.

Before starting to write, be sure to think about what the question is, what answers are being asked for, what answers might make sense, and what your intuition is.
All the information you need is given in these questions.
You may have misinterpreted the question if you think you don't have the right information.
It's easy to get confused in some calculations, so think about whether your answers make sense in terms of what the question is asking.
If you know what the answer should look like before you start writing, you won't waste time on dead-ends.

The study of physics will show up all over the place.

displacement, velocity, acceleration, force, momentum, and electric and magnetic fields are some of the physical quantities that are represented as vectors.
The purpose of this chapter is to provide you with a mastery of the fundamental vector algebra we'll use in subsequent chapters, since it's important to become comfortable working with them.
We'll only be studying twodimensional vectors for now, because they lie flat in a plane.

Mass, work, energy, power, temperature, and electric charge are examples of scalars.

When they have the same magnitude and direction, there is no difference.

If there is a negative sign only, the multiplication shows a change in magnitude by the numerical multiple and direction.

A car travelling east at 100 km per hour is an example of this.
The car's new speed is 200 km per hour.

A number can be used to make avector, which is a multiplication by a number.

The process will follow the tail to end convention if we add the negative of B.

If you are not using a coordinate system, pay attention to direction.

If you set a point to the right as positive, you have to set a point to the left as negative.

Any part of a plane can be described in this way.

The magnitude can be computed using the Pythagorean Theorem.

This is an interpretation of the Pythagorean Theorem.

It's important to brush up on geometry and trigonometry.

The inverse trig function can be used to determine the angle.

The plane can be written in terms of two parallel component vectors.