PE HW Quiz Answers are attached: If you missed these last Friday, you were to be looking for this posting, with the answers as they are supposed to be.
I'm also writing below the Ballistic Pendulum Speed answer you were supposed to work on in class. I wrote it on the board under the clock, and I repeatedly told people to work on it: If the Coffee Can (with dart)'s low point was called Point A, and it's high point as it swung in the arc was called point B, then you were given time to work on the following and ask questions about them. Assuming Can mass was 100 g (with dart), and point B is 0.4 cm higher than point A:
KE at A was unknown
PE at A was assigned as 0
ME at A was unknown And you were to solve for speed at A.
KE at B was 0
PE at B was 3.92 times 10 to the -3 J. (AKA 3.92 mJ) Calculation was covered thoroughly.
ME at B was 3.92 times 10 to the -3 J. (AKA 3.92 mJ)
This means ME at A was 3.92 times 10 to the -3 J. (AKA 3.92 mJ)
PE at A was 0
This means KE at A was 3.92 times 10 to the -3 J. (AKA 3.92 mJ)
Therefore, from KE, v at A is calculated to be 0.28 m/s.
A student who doesn't go through the logic above is behind on Chapter 5, and needs to have questions in class ASAP. None of the above logic is new. It's the kind of problem that's covered repeatedly on the Chapter 5 Practice Tests.
If you didn't work on the Pendulum problems above as instructed, or didn't get the answers above, but never asked questions about these exercises, then you fell behind. But maybe that didn't happen for many individuals, and maybe for them, the Chapter 5 Test on Thursday will be as simple as I intend it to be.