A research group investigated how different colored materials underneath a tea cup affected the temperature of the tea over time to help determine time of death in a murder case. They hypothesized that a tea cup placed on a purple index card would best maintain the tea's temperature. The group measured the initial and subsequent temperatures of tea in cups placed on index cards of various colors over two hours. Their data tables and graphs showed that the tea cup on the purple index card had the smallest decrease in temperature over time, supporting their hypothesis. However, they noted limitations in their experiment regarding equipment and exact locations of the tea cups.

1. Investigating a Murder Testing the effect of colors on the temperature of tea Catherine Horelick Period 6 Tara Ramirez Chemistry LH Satish Bhat 12/23/10

2. Problem Statement A murder is being investigated CSI teams are trying to use tea temperature to find Time of Death (TOD) Research group is placing different materials underneath tea cup Finding correlationbetween the color (IV) underneath the tea cup and the temperature of the tea (DV) Catherine Horelick Tara Ramirez Satish Bhat

3. Introduction / Hypothesis Expecting purple paper to maintain the temperature of the tea the best If different color index cards are placed under a tea cup, the tea cup placed on the purple index card will maintain the temperature of the tea the best Based on prior research: White light is a mixture of colors Light colors reflect white light Dark colors absorb white light Catherine Horelick Tara Ramirez Satish Bhat

4. Procedure Gather materials Measure 50mL of tap water in graduated cylinder Pour water into tea cup Repeat steps 2-3 for four more tea cups Measure initial temperature of water Repeat step 5 for all tea cups Place two purple index cards next to each other (in the sun) Catherine Horelick Tara Ramirez Satish Bhat

5. Procedure Continued 8. Repeat step 7 for other colored index cards 9. Place a tea cup on the purple index cards 10. Repeat step 8 for other colors 11. Wait five minutes 12. Take temperature of each tea cup 13. Record data 14. Repeat steps 10-12 for two hours 15. Analyze data and prepare graphs and data tables Catherine Horelick Tara Ramirez Satish Bhat

6. Data Tables DISCLAIMER: ALL TEMPERATURES NOTED ON THIS SLIDE ARE IN DEGREES CELSIUS Catherine Horelick Tara Ramirez Satish Bhat

7. Graphs Catherine Horelick Tara Ramirez Satish Bhat

8. Equations White Paper y = -0.001x2+ 0.013x + 42.02 Purple Paper y = -0.00005x2 + 0.052x + 42.81 Green Paper y = -0.001x2 -0.003 + 42.54 Yellow Paper y = -0.063x + 42.78 Red Paper y = -0.019x + 42.74 Catherine Horelick Tara Ramirez Satish Bhat

9. Validity Discussion This experiment was carried out well All cups were run at the same time Cups were placed near each other but because they were all being rested at the same time, they were in slightly different locations Equipment was not readily available Thermometer used only went to 45°C limiting range of temperatures Catherine Horelick Tara Ramirez Satish Bhat

10. Investigating a Murder By: Tara Ramirez, Catherine Horelick, and Satish Bhat