Homework Due Thurs Jan 31

Read 14.3
Problems 29, 51, 54, 57, 84

Reminder: Homework Harvest and Ch 14 Quiz

The next Homework Harvest will be Thursday, Jan 31.

The Chapter 14 Quiz will be Monday, Feb 4.

Homework Due Tues Jan 29

Read 14.2
Problems 15, 17, 21, 23, 33, 39, 80

Homework Due Jan 25

Read 14.1. Do problems 10, 11, 12, and 13.

Heat Saver Contest Reminder

Hi All,

Just a reminder that your heat saver device is due this Wednesday, January 23rd.  The project is worth 20 points; here is the point breakdown:

12 points: Report (you do not need to include standards or a group number)
5 points: Your device meets the specified criteria (fits through 50cm hoop, holds 250ml water, etc.)
3 points: How well your device minimizes heat loss (top 1/3 of the class gets 3 points, next 1/3 2 points, etc.)

Please include the following text at the end of your report.  You will fill in the numbers in class.  Have your report completed before class on Wednesday, as you will have minimal time to work on it in class.

Initial Temperature (T_i)             ________°C
Final Temperature (T_f)             ________°C
Change in Temperature (ΔT)  ________°C
Heat Lost (Q = mcΔT)             ________Joules 
Rate of Heat Loss (Q/time)     ________Watts


Thanks in advance for your hard work!

Mr. Holthaus

Chapter 12 Quiz Review Packet

Here is the review packet in case you were absent today:

https://docs.google.com/file/d/0B1IH6SaYBYNTU2tGRkVGN2FOM3M/edit

Just a reminder, the quiz this Friday will be no notes, no book.  Feel free to email me if you have any questions about the review packet.

--Mr. Holthaus

Chapter 12 Section 1 Quick Quiz Solution

Since we didn't get to go over the quickie quiz in class today, here is a video of the solution:

http://youtu.be/YpDlH0Q2otY

Homework Due Jan 16th

Ch. 12, problems 41, 64, 66, 67

Homework Due Jan 14th

Read Section 12.2
Problems: 28, 29, 34, 53, 61, 62

Turn in labelled drawing of your planned heat saver device

Heat Saver Contest: Container Due Jan 23

Heat Saver Contest

 

Purpose:    

Design and build acontainer which will:

1      Make your sampleof water have the smallest possible drop in temperature

2      Make your samplehave the lowest rate of heat loss (in watts)

3      Have the smallestmass

4       Prepareyour lab write up beforehand. Write down your formulas so you can plug in numbers in class.

 

Rules:

1.   Your container may be built of heatinsulating materials – but it must be constructed.  You cannot use a manufactured thermosbottle etc.  Foam materials, cups,cozies, packing materials, etc may all be used.  You can’t use your soup or hot chocolate thermos, etc.

 

2.   Your container must be built outside ofclass, no construction allowed during class.

 

3.   Your container must not be larger than 50cmon any side, including internal and external diagonals.  Your container must pass through a 50cmhoop unabated no matter which way it is oriented.

 

4.   Your container must hold 250 ml of waterwithout overflowing.

 

5.   Your container must provide for quick andsimple insertion and removal of a glass thermometer into the middle of yoursample.  The middle of your samplemust be no more than 25cm from the insertion spot.

 

6.   Your entire container must be at roomtemperature when the water is placed into it.

 

7.   The starting temperature of your sample willbe read and recorded at a specified time. The final temperature will be read 15 minutes later.  During this time, the container mustnot be disturbed in any way.  Itmust not be in contact with nor contain anything which might serve as a sourceof heat energy. 

 

8.   Your container must be supported only by thelab bench.  Any item touching thecontainer will be considered part of the container and added to the mass of thecontainer.

 

9.   Temperature will be measured at the bottomcenter of container.

 

Report

Your report is due15 minutes before the end of class in order to get a score and must include:

1)   Title

2)   Standards

3)   Group number

4)   Member names

5)   Date

6)   Period

7)   All data and calculations (heat loss inwatts)

8)   A briefstatement about how your design minimizes heat lost by each of thefollowing mechanisms: CONDUCTION,CONVECTION, and RADIATION

 

Judging –Equal weight will be assigned to 4 categories and highest points will beawarded for:

1)   Minimum temperature drop of water

2)   Minimum mass of container   

3)   Minimum rate of heat loss in watts

4)   Maximum Neatness, completeness, and accuracyof report

Homework Due Jan 10th

Read Section 12.1

Problems:
p. 322 #12, 15
p. 336 #47, 50
p. 337 #57, 63