MCHV10702: Re-Cap of Physics II

Hey everyone,

Let’s briefly discuss the preview assignments for Gen Chem II:

These chapters cover the following topics: Compounds & Stoichiometry, Kinetics & Equilibrium, Thermochemistry, Phase & Phase Changes, and Solutions!
That is quite a load. If your time is extremely limited, prioritize the three online workshops first. Each one of them is excellent and provides a wealth of high-yield information.

If you only have time for one OWQ right now, please complete this one. The very first passage of the lesson will test you on how to determine the rate law from trial data. This OWQ does a nice job in showing you how to work through the math. Don’t just look at the slide and nod your head along. Test yourself, and learn how to determine the rate law quickly.

Although direct questions regarding the properties of solutions are rare, problems that integrate your knowledge of solutions into other problems are common. Memorizing all of the solubility rules is a bit of overkill…the more important slides in this workshop are the slides that review units of concentration. Definitions and examples of percent composition by mass, mole fraction, molarity, molality, normality and dilutions are thoroughly reviewed here. Finally it concludes with a thorough discussion of colligative properties (notice that osmotic pressure is listed there! This maps well to the examples of osmosis we discussed in Biology I).

This OWQ reviews all reaction types, but we will not cover redox reactions until Gen Chem III.

To reinforce what we have covered in Physics II, complete the following (please also see notes below):

All of these items are available on your syllabus through www.kaptest.com

Before we jump into our review, one note:

Physics II is a tough lesson; don’t be discouraged if you don’t understand everything right away. If the concepts of simple harmonic motion, electrostatics or circuits aren’t clear to you now, spend some time with the Physics II Foundation Review. And don’t forget that your Review Notes are also online in a “cafeteria menu” organization. This means that you can revisit the review notes by topic rather than by chapter. You can find the review notes in the “My Tools” tab on your kaptest.com homepage. Also, make sure to check out the attached document that walks you through the example circuit we looked at in class.

When you review your notes from our Physics II session, focus on these key points:

Review each type of process from the Review Notes (isothermal, isobaric, isochoric, adiabatic) and test your understanding of each conceptually as well as quantitatively via the equation ΔU = Q – W_{by sys}. Revisit Question 4 and see if you can explain why C is the correct answer without referring to the graph!

Restoring force (for springs + pendulums)
Angular frequency, frequency, period (for springs + pendulums)
Expression for the potential energy of a spring
Expression for the total mechanical energy of a spring (energy is proportional to AMPLITUDE²!)
Understand when a mass oscillating at SHM is at max KE and max PE; be able to identify the directions of acceleration, velocity and displacement

Standing waves are created when a propagating wave reflects off of a boundary; the reflected wave interferes constructively and destructively with the waves that are propagating toward the boundary. Standing waves are called such because they appear to be “standing still”; the only evident movement is an oscillation of amplitude.
There are two types of boundaries which can help create standing waves: closed and open. Closed boundaries include the attachments of guitar strings to the guitar or the end of the flag that is secured to the flag pole. Open boundaries include the distal end of an oboe or the end of the flag that is flapping in the wind.

What is a wave?
What properties of a wave can we determine from a plot of the wave’s displacement versus time? What properties can we determine from a plot of a wave’s displacement versus distance?
What is the wave speed formula?

Recall that the velocity of a wave is dictated by its medium. Within a given medium at a given temperature a wave’s velocity will not change. The speed of a wave changes only if the wave moves into a new medium or if the temperature of the medium it is propagating through changes.

What are the units of intensity?
What property of a wave is related to its intensity? What is the relationship – linear or exponential?

Did you notice that the relationship between the total energy of a spring and amplitude is exactly the same? Cool, right?

What is the difference between an electromagnetic wave and a pressure wave? What is the difference between a transverse and longitudinal wave?

For an animation that diagrams the different types of wave motions visit this link: http://www.kettering.edu/~drussell/Demos/waves/wavemotion.html

Decibel scale: know that an increase in 10 decibels is equivalent to increasing the intensity by a factor of 10.

Also, here are some comments about the topical tests associated with Physics II:

Comment: this test has a lot of solid conceptual questions. The 2^nd passage is tough, but that’s good because you’ll learn from it.

Comment: The first passage is a bit out there, but the 2^nd passage is fantastic. RC circuits are not discussed anywhere else, and although you are not “officially” expected to be familiar with them it is in your best interest to understand how they work because of their applicability in many applications.

Comment: don’t allow yourself to get psyched out by the new info in either passage.

Comment: three of the questions associated with the first passage are mathematical, but question #1 and #4 are good conceptual questions. In general, many students find the first passage to be one of the most difficult physics passages in our entire library. Some of you may find the second passage weird, but the questions there are a bit easier.

See you at Gen Chem II!

MCHV10702