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Rate of Cooling Experiment
Rubric

9th Grade Performance Task
Developed by: RAND Corporation (RAND)
Stanford University and the Far West Laboratory, 1994

Rate of Cooling Analysis
Scoring Rubric

#1 (pg.2)

1a Graph - Axes

1.1 Labeled (1 point for "time", 1 point for "temperature")

1.2 Appropriate units specified

  • "seconds or "minutes" for time
  • "degrees Celsius", "degrees", or "Celsius" for temperature.

1.3 Equal Intervals (if origin is 0,0 and there is a gap in numbering for an axis, no credit for that axis unless a break in the graph is correctly indicated)

1.4 Time on x-axis (indicated by "time", "seconds" or numbering of axis with "60, 120, 180"

1b Graph - Trials

1.5 Plotted and identified

  • any points plotted
  • key, labels, or colors must be used to permit identification of trial by letter, number of fabric

1.6 Line graph drawn rather than bar graph (points must be connected in conventional manner).

1.7 Single set of axes used for all 3 trails (give credit for single set of axes labeled but slightly staggered plots drawn.)

1.8 All 6 data points plotted (or 6 bars) per trial

1c Graph - Results

1.9 Proper slope (all plots indicate cooling)

1.10 0 sec. = 37 deg. Celsius for all three trials. (If equal intervals are used, can infer the 0 on the x axis, don't need "0" or "start" to give credit for 0 = 37 deg.)

1.11 End points in order: 3>1>2 (if separate graphs are used but not identified, can assume that trial 1 is on the left.)

#2a (pg. 3)

Trials

2a.1 Pattern (1,1,1,1,1)

  • Numbers must be used
  • Entire pattern must be described
  • Rate must be indicated ("degrees Celsius/min." is best; "degrees for each time interval" is acceptable.)
  • Rates of cooling for minutes 1-5 of trial 1, in deg. Celsius/min. are 1,1,1,1,1 (rate is constant). (note: for this trial only, "it decreased 1 degree per minute" or "it was 1 degree perminute" is given credit for both summary and pattern information.)

2a.2 Summary - mean rate, total change or comparison of rate, speed or amount of temperature change

makes an accurate (but can be approximate) statement about one of these features of trial 1:

  • average change (e.g. "it decreased 1 degree per minute")
  • total change (e.g. "it changed 5 degrees", endpoints alone are not sufficient)
  • comparison (e.g. "the temperature decreased more slowly than trial 2" (Note: if comparison is made to a specific other trial, give summary credit for both trials)

#2b (pg. 3)

2b.1 Pattern (2,1,2,1,1)

  • Numbers must be used
  • Entire pattern must be described
  • Rate must be indicated ("degrees Celsius/min." is best; "degrees for each time interval" is acceptable)
  • Rates of cooling for minutes 1-5 of trial 2, in degrees Celsius/min. are 2,1,2,1,1

2b.2 Summary - mean rate, total change or comparison of rate, speed or amount of temperature change

makes an accurate (but can be approximate) statment about one of these features of trial 1:

  • average change (e.g. "it descreased 1 1/2 degrees per minute")
  • total change (e.g. "it changed 7 degrees", endpoints alone are not sufficient)
  • comparison (e.g. "the temperature decreased more slowly than trial 1" (Note: if comparison is made to a specific other trial, give summary credit for both trials)

#2c (pg. 3)

2c.1 Pattern (2,1,2,1,1)

  • Numbers must be used
  • Entire pattern must be described
  • Rate must be indicated ("degrees Celsius/min." is best; "degrees for each time interval" is acceptable)
  • Rates of cooling for minutes 1-5 of trial 3, in degrees Celsius/min. are 1,1,1,0,1

2c.2 Summary - mean rate, total change or comparison of rate, speed or amount of temperature change

makes an accurate (but can be approximate) statement about one of these features of trial 1:

  • average change (e.g. "it decreased 1 degrees per minute")
  • total change (e.g. "it changed 4 degrees", endpoints alone are not sufficient)
  • comparison (e.g. "the temperature decreased more slowly than trial 2" (Note: if comparison is made to a specific other trial, give summary credit for both trials.)

#3 (p.4)

3.1 Equation: Q = V x T (can also multiple by 1 (specific heat of water))

3.2 V column (all 6 correct values)

3.3 T column (all 6 correct values)

3.6 Q column (5 of 6 correct values)
column Q has at least five of the six calorie calculations correct

#4a (pg. 5)

4a.1 Trial 5 identified as trial with the greatest change in temperature.

#4b (pg. 5)

4b.1 "20" written (with or without degrees Celsius or degrees)

4b.2 degrees Celsius or degrees used as unit

#5a (pg. 5)

5a.1 Trial 4 identified as trial with greatest heat loss

#5b (pg. 5)

5b.1 "3200" written (with or without "calories")

5b.2 Calories used as units

#6 (pg. 5)

6.1 Reason given for rate difference

  • Examples: random error, difference in ice water temperature, different air temperatures
  • reason must not be volume or fabric

#7a (pg. 5)

7a.1 Trials 4 & 5 or Trials 5 & 6 used to observe the effect of volume

#7b (pg. 5)

7b.1 Volume varies - student states that cans have different volumes

7b.2 Same color

  • asserts that the two trials have identical fabric conditions (no fabric) or
  • states that the conditions are the same except for volume

#8 (pg. 6)

8.1 Volume effect - directly or indirectly indicates that the rate of cooling is greater for smaller volumes or less for larger volumes.

#9a (pg. 6)

9a.1 Fabric C is best.

#9b (pg. 6)

9b.1 Evidence from experiment to support choice

Notes:

1. general reference okay, for example: "fabric C kept the water the warmest" or "fabric C lost less heat"
2. Indirect reference okay, for example, "because the temperature decreased the least"
3. Do not give credit if experimental evidence not mentioned (no credit for only "fabric C was proven to be the best" or "fabric C is made of wool").

9b.2 Specific data - Answer cites numbers from Tables 1 or 2 (or numbers that can be derived from the tables, such as calorie calculations or graph points.)

 

Rater Answer Form - Cooling Analysis

Rater Name: ___________________________

Rater ID Number ___________________

1a. Graph - Axes (1 for each axis        
Labeled (time and temp)
0
1 2  
Appropriate units specified (seconds, minutes, degrees) 0 1 2  
Equal intervals 0 1 2  
Time on X-axis 0 1    
1b. Graph - Trials        
Plotted and identified (1 per fabric) 0 1 2 3
Line graph 0 1    
Single set of axes 0 1    
All 6 data points plotted for each trial 0 1    
1c. Graph - Results        
Proper slope 0 1    
0 seconds = 37 degrees 0 1    
End points in order: 3>1>2 0 1    
2. Trials (Summary = mean; total D; compare speed, rate, amount)        
Trial #1 - Pattern (1,1,1,1,1) 0 1    
Summary 0 1    
Trial #2 Pattern (2,1,2,1,1) 0 1    
Summary 0 1    
Trial #3 Pattern (1,1,1,0,1) 0 1    
Summary 0 1    
3. Formula and Table        
Equation Q = V x DT 0 1    
V column (6 correct values) 0 1    
DT column (6 correct values) 0 1    
Q column (5 of 6 correct values) 0 1    
Table (at right) V
200
200
200
200
50
200
DT
5
7
4
16
20
15
Q
1000
1400
800
3200
1000
3000
 
4. Greatest change: 1 = Tr.5, 1 = 20, 1 = degrees 0 1 2 3
5. Greatest heat: 1 = Tr.4, 1 = 3200, 1 = calories 0 1 2 3
6. Reason: 1 = e.g., chance, variation in air or ice water temp, other... 0 1    
7. Compare volume:        
1 = Tr.4/5 or 5/6 0 1    
1 = Volume varies 0 1    
1 = Other variables remain the same (e.g. fabric) 0 1    
8. Volume effect: 1 = faster cooling with smaller volumes 0 1    
9. Which fabric:        
Fabric C 0 1    
Evidence from experiment 0 1    
Specific data - quantities from table, curves on graph 0 1    

 

 


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