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Thursday, February 28, 2013

Chapter 5 HW



1. Science Workbook pp. 49-57, 61, 62
      2. Science Reading Essentials pp. 73-82
      3.   Text pp. 158-159 #1, 7-10, 13-15

Friday, February 1, 2013

Lab #7 – Heating Up and Cooling Down



Lab #7 – Heating Up and Cooling Down

Do you remember how long it took for a cup of hot chocolate to cool before you could take a sip? The hotter the chocolate, the longer it seemed to take to cool.

Problem
 How does the temperature of a liquid affect how quickly it warms or cools?


Hypothesis



  
Materials
3 beakers
3 thermometers
Stopwatch
Ice
Hot plate
100 mL Graduated Cylinder

Procedure
  1. Use the data table to record the temperature of water in three beakers every minute from 0 to 10 min.
  2. Fill one beaker with 100 mL of water. Place the beaker on a hot plate and bring the water to a boil. Carefully remove the hot beaker from the hot plate.
  3. Record the water temperature in your data table at minute 0, and then every minute for 10 min.
  4. Repeat step 3 starting with water at room temperature and ice water.
  
Results
Ice Water
Time (min.)
Temperature ('F)
Temperature ('C)
0
 32’F
0’C
1


2


3


4


5


6


7


8


9


10


  
Room Temperature water
Time (min.)
Temperature ('F)
Temperature ('C)
0


1


2


3


4


5


6


7


8


9


10




Boiling Water
Time (min.)
Temperature ('F)
Temperature ('C)
0
 212'F
 100’C
1


2


3


4


5


6


7


8


9


10



 Analysis

1.                   Graph your data for all four beakers; use only your temperatures in Fahrenheit!  Use a different color for each beaker.

2.                   Infer from your results how the difference between room temperature and the initial temperature of the water affected the rate at which it heated up or cooled down.





3.                   What happened to the temperature of the boiling water?
4.                   What happened to the temperature of the ice water? 
5.                   What happened to the temperature of the room temperature water?
6.                   Do you think there will be a temperature at which they would eventually meet?  If so, where do you think it will be?  If not, why not?
7. What was your independent variable?
8. What was your dependent variable?
9. What remained constant?


  
Conclusion

 What was your problem?
 Restate your hypothesis.  Was it right? wrong?  why or why not?
 What did you learn in this lab?
 What did you like about this lab?
 What were some challenges you had to deal with?
 What could you do next with this problem?  What other tests could you perform?
 Write down any other additional thoughts, observations, inferences, etc.




LAB #6 – Measurement: Volume

Introduction
Volume is the amount of space occupied by matter - solid, liquid, or gas.
Volume is measured in units: cm3 for a solid, mL for a liquid. 

Problem
-         A: How can we find the volume of a rectangular block? 
-         B: How can we find the volume of an irregularly
           shaped object?

Hypothesis:
-

Materials
-         Various sized blocks, irregular shaped objects, ruler, graduated cylinder

Procedure A
 1) Use a metric ruler to measure the dimensions of your rectangular objects; measure to the nearest tenth (0.1) cm.
 2) Calculate the volume in cm3 of your rectangular object by multiplying the length (cm) times the width (cm) times the height (cm). V = L x W x H
 3) Record your measurements in the data table.

 Results
Data Table: Volume of rectangular objects
        
Object
length (cm)
width (cm)
height (cm)
Volume (cm3)
 A



 
 B




 C




 D



  
V = L x W x H
cm3 = (cm)(cm)(cm) 
  
Procedure B
Use a graduated cylinder to measure the volume of an irregular shaped solid. 
1. Fill the graduated cylinder to 50 mL and record this into your notebook.  This is your initial volume.
2. Carefully drop the object in on an angle.  The object will displace water (push water up to make way for the object) which will rise to make a new volume.
3. Subtract your initial volume from the new water level.
 Final Volume --------------à                _____mL
- Initial Volume ------------à                 _____mL
=Volume of irregularly shaped object: _____mL

Analysis
1) What is the maximum volume you can measure with this graduated cylinder?
2) What is the smallest volume you can measure with this graduated cylinder?
3)  Determine the value of the minor grids on the cylinder.  i.e. how many mL does each line equal?

Now, check to see if you’ve measured correctly using the Volume of a sphere equation:                                                  
Volume of sphere using equation:_____cm3





Conclusion


 What was your problem?
 Restate your hypothesis.  Was it right? wrong?  why or why not?
 What did you learn in this lab?
 What did you like about this lab?
 What were some challenges you had to deal with?
 What could you do next with this problem?  What other tests could you perform?
 Write down any other additional thoughts, observations, inferences, etc.