Monday, February 24, 2014

Payment for Science Classes

Hi folks,

Just a reminder, that payment is due for the final session of classes. The cost is $250 for the full 2 hour class and $180 for the 1.5 hour class.

If you wish to mail your payments, my address is 3105 Whitfield Rd. Chapel Hill, NC 27514.

I hope everyone is enjoying this wonderful spring-like weather.

Jim Mueller

Tuesday, February 18, 2014

Recording of Physics week 21: Working with Energy Formulas

This is short since most of the class was lab work.

Way to go, ScienceJim!
Your video is now on YouTube.
 Physics week 21
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2/18 Physics class update and homework due 2/25

Hi folks,

Today we began the next part of our energy unit with is energy in motion, in other words, waves. Today we worked on the concept of frequency and hertz.

In order to work with this, the students created 3 pendulums. One of which had a frequency of .5 Hz, one had a frequency of 1 Hz and the last had a frequency of 2 Hz. From their data, they then predicted what length of string would have a frequency of 1.5 Hz.

Extra Credit possibility. Continue working with pendulums and do a lab exploring one of the many variables you thought of today during class. For example, changing the weight of the bob. Does the height of the swing matter? Does interference of the swing matter.

Homework due 2/25

Read Conceptual Physics pgs 103-118
Do Review Questions pg 119 and 120 #'s 7-12, 18 and 20
Do Plug and Chug pg 120 #'s 4-7
Do Think and Explain pg 120 and 121 #'s 2 and 3.

Thursday, February 13, 2014

PDF for homework

Here's the .pdf for the homework this week. It seems to have not attached last time.

Physics update for 2/11 and homework due 2/18

Hi Folks,

Sorry about how late this is.  I thought I sent this out on Tuesday night.

Today we got into the concept of Potential and Kinetic energy and how they change into each other.  We also discussed energy efficiency and conservation of energy.

For homework this week:

Find the energy the ramp stole from the ball (if you haven't already finished that in class). 

Find the energy efficiency of the ramp.  Take the work out (the energy the box was hit with) divided by the work in (the potential energy the ball started with) and multiply that by 100 to convert it to a percentage.

Read the Potential and Kinetic Energy chapter in the eBook

Open the following simulation and use it to answer the following questions in the .pdf.

http://phet.colorado.edu/en/simulation/energy-skate-park

Tuesday, February 4, 2014

2/4 Physics update and homework due 2/11

Hi folks,

Today we continued our investigation into simple machines and their relation to work. We did some work with pulleys and discovered the inverse relationship between distance and force.

For homework this week:

Read the pulley chapter in the book.

Take a look at the enclosed .pdf and do all the questions at the end.

Also, answer the following questions.

1. With the pulleys, how did work out relate to work in?

2. With the levers, did work out relate to work in? It should have. So what wasn't measured that caused work out to not relate to work in in the same way as the pulleys?

3. What relationship did force have in regards to distance as you worked with the pulleys?

4. As you increased the number of pulleys, what effect did that have on the effort force? What effect did it have on the effort distance?

5. a. If you were lifting a load that required a force of 10N with one pulley, what effort force would be required?
b. Same question, but now you're using 2 pulleys?
c. How about 10 pulleys?

6. a. If you were lifting that load 1 meter, what would the work in distance be for one pulley?
b. 2 pulleys?
c. 10 pulleys?