# Tasks to do

## General Q&A

1. Can I type solutions on word doc and upload it to media manager?
• It's much more preferable to type straight into the wiki, so that others can edit it.
• Don't make it perfect all at once, but just start or continue something, and others will take care of it.
2. I posted a comment on Wiki. Do I have to write my name underneath it?
• No need to sign your name, unless it’s a personal question. The wiki software automatically keeps track of who edited what. Every few weeks or so I check that record and give you points.
Prof. Nicholas Kuzma 2015/04/13 13:08

## Immediate priority

Task Rough first pass “Make it look nice” edit Error check and fix
Create a class calendar for us (see below) Brittany D
Post solution to Problem 1.0
Post solution to Problem 1.2A Elin O Prof. Kuzma
Solve Problem 1.2A when k is unknown

### Task: create our calendar

Steps:

1. open a new g-mail account with an appropriate name (such as PSU.physics203.2015)
2. go to the calendar (http://calendar.google.com)
3. log in with the newly created account name and password
4. add all the dated events from the syllabus.
5. email Prof. Nicholas Kuzma the name and password for the account

### Having trouble?

Post your questions or tips below:

1. Question: I cannot figure out how to edit the already created calendar to add new items.
• Answer: You need to log in into Google calendar. I'll send you the login info. — Prof. Nicholas Kuzma 2015/04/28 00:03
2. Question:
3. Question:

## Medium priority

Task Rough first pass “Make it look nice” edit Error check and fix

### Questions?

Post what's on your mind below:

1. Question:

## Wish list

Task Rough first pass “Make it look nice” edit Error check and fix

### Ideas?

Post your suggestions below:

1. Question:

# Other postings

## Putting out fire with sound

I just found this interesting and relevant to what we are discussing in class. George Mason University engineers use low-frequency sound waves to put out a fire.

## Homework questions

1. Question:A 0.550-kg block slides on a frictionless horizontal surface with a speed of 1.40 m/s . The block encounters an unstretched spring and compresses it 23.0 cm before coming to rest. What is the force constant? I tried using $\frac{1}{2}mv^2= \frac{1}{2}kx^2$, but I couldn't figure out what x was. Then, I tried $k=\frac{mg}{x}$ and that wasn't the right answer either. — Brittany D.
2. Question:How do you know which direction a wave is travelling based on harmonic wave function equation (e.g. homework 14.23
• Answer: In the harmonic wave function equation look at the sign of x and t (– , +). If they have the same sign then the wave is travelling in the negative x direction.
• If x and t have different signs, the the wave is moving in the positive x direction.

Molly McCarthy 2015/04/14 10:47