Physics C pre-derived formulas

Test Preparation AP Sciences
1

<p>Anyone no to what extent we can use formulas that are already derived for us? There are some real nice ones in review books that are not found on the formula sheet. To be specific I really want to know if these can be used on the free response:</p>

<p>v’(2) = v(1) * (2 * m(1)) / (m(1) + m(2))
v’(1) = v(1) * (m(1) - m(2)) / (m(1) + m(2))</p>

<pre><code> These are used in head-on elastic linear collisions with the first object having velocity v(1) and the second object starting at rest.

I rather not waste time doing tedious manipulations of the same formulas if I can just remember what is going to be derived.
</code></pre>

2

<p>I don’t think it is a right approach to remember formulas except the very basic ones.</p>

3

<p>I’m normally against formula memorizing over conceptual understanding but…</p>

<p>Heck yes. Remember that ugly guy. Why? Because deriving this guy leaves a ton of room to make mathematical mistakes too. Simply have the conceptual understanding behind it and keep the formula at your hand to bash it. Write your conceptual reasoning down on the AP test when required / “original” formulas that build up to this.</p>

<p>There aren’t too many formulas on the list to remember, but this is one of them.</p>

4

<p>^I disagree…I think it’s much more likely to make an error in memorizing that big complicated formula than it is to make an error deriving the formula. It’s just algebra, it shouldn’t be that tedious.</p>

5

<p>You guys are allowed formula sheet in exams?</p>