3/30 Physics update and homework due 4/6

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 4/6

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.

Never Stop Wondering

"Science Jim"  Mueller

(919) 929-9791

A Fun Approach to Serious Physics!

Sciencejim

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Link for the simulation for the physics homework

Hi folks,

I sent the homework but I don't think I sent the link to the simulation on PHET.  Here you go.

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

Never Stop Wondering

"Science Jim"  Mueller

(919) 929-9791

A Fun Approach to Serious Physics!

Sciencejim

Join my Facebook page!

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3/23 Physics update

Hi folks,

Today we spent a lot of time on the inverse relationship between potential energy and kinetic energy.   We also did a lab where the students compared the energy of two different objects using two different techniques.  They also looked at energy "lost" due to friction.  Lastly, they predicted the behavior of a final trial based on a graph of their previous trials.

1. Homework for 3/30 is to do the enclosed document and answer the following questions about the lab.

2. What was your percentage error between your prediction and your actual result?  

% error = (prediction - actual) / actual x 100, in absolute value.

3. Which of the balls was the most energy efficient?  In other words, which transferred most energy to the cart?  Please show me your calculations for all four balls.  

Energy efficiency = Work in (ball rolling)/ work out (cart moving) x 100.

What hypotheses can you make based on the results you saw?

3/16 Physic update and Homework due 3/23

Hi folks

Today we went over more details on work and energy and simple machines.  We also began talking about Potential and Kinetic energy.

For homework this week, read the Potential and Kinetic energy chapter of the eBook.  Also, give a try to the enclosed .doc.  It covers a lot of what we've done in class so far so it may be a bit challenging.  Feel free to email me with any questions.  Good Luck!

Another great science joke

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> Jim,
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> When I was a chemistry major at Cornell we had this one:
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> "The radius of the stain produced on the ceiling is inversely proportional to the force of the explosion!
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> Best
> Jim Chickos
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3/9 Physics update and homework due 3/16

Hi folks,

Today we spent some time with W=FxD and how it relates to simple machines.  We learned that simple machines basically swap distance for force to make the work easier to accomplish.  We did a lab with pulleys today to illustrate the point.

Homework for this week is to: 

Read the "Pulleys" chapter in the eBook I sent last week.

Read 111 to 114  in the Conceptual Physics book

Take a look at the data from this weeks experiment and answer the following questions.

1.  How did work in (work you did) compare to work out (work on the battery).?

2.  Did work change much for work in?  Did it change much for work out?

3.  Did force change for work it?  How about distance?

4.  What was the relationship between the change in distance and the change in work?

5.  What is the point of using pulleys?  If the work is always the same, what does the pulley do for you?

6.  Is there a disadvantage to using pulleys?

Answer review questions on page 120 #'s 13, 14, 15, 16

Plug and Chug questions #'s 8, 9

Never Stop Wondering

"Science Jim"  Mueller

(919) 929-9791

A Fun Approach to Serious Physics!

Sciencejim

Join my Facebook page!

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Wrong problem in the homework

Hi folks,

I listed 2 and 4 in the Think and Solve problems.  It should be 2 and 3, we haven't gone over potential energy yet.

Sorry for the confusion on that.

Never Stop Wondering

"Science Jim"  Mueller

(919) 929-9791

A Fun Approach to Serious Physics!

Sciencejim

Join my Facebook page!

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3/2 Physics update and Homework due 3/9

Hi folks,

Last week we did a nice conceptual overview of what energy is and this week we got a bit more into the nitty gritty and mathematics behind energy.  We introduced the concept that energy is the ability to do work and that work is equal to force times distance.  To make that more concrete, we figured out the amount of energy it takes to lift ones body off the ground by jumping and then we figured out the amount of energy it takes to climb a 3.15 m set of stairs.  After we saw what energy we used to climb the stairs, we used the time it took to climb the stairs to get our power in Watts.  Power is work divided by time.  We then compared our power to the power it would take to run light bulbs, computers, water heaters etc. 

In my opinion the text that we're using goes into too little detail on energy.  I'm including my Energy eBook to help supplement the text

Homework for due 3/9 is to 

Read pp 103 and 104

Read the Energy and Work chapter in the eBook

Do Review Questions on page 119 #'s 1 - 5

Plug and Chug Pg 120 #'s 1 and 3

Think and Solve # 2, 4

Extra Credit:  Do the "Find the Power" experiment in the eBook.  We did the first part where you find your wattage in class.  (Email me if you can't remember your wattage.) Compare yourself to at least 5 different appliances.

Great Picture

A great picture shared by the Chemistry students.

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