**Task Name : **Coffee Cup Experiment |
**Task Level : **J (Year 9) |

**Semester : **1 |
**Topic :** Comparing Fractions |
**VC Strand : **Real Numbers |

**Web Address : **http://maths.crusoecollege.vic.edu.au/rnJ |

**Equipment Needed : **Thermometers; cups of various materials (plastic, ceramic, polystyrene); measuring cylinders. |

**Victorian Curriculum outcome : **Solve problems involving direct proportion. Explore the relationship between graphs and equations corresponding to simple rate problems |

**Task description :** .Students conduct an experiment to determine the rate of cooling of hot water in various coffee cups. Students observe the cooling of 100mL of hot water in a polystyrene cup over ten minutes and record the data in a table. Students plot the graph showing temperature vs time. Students draw a line of best fit, and use both the raw data (from the table) and from the line of best fit to find the rate of cooling. Students then extrapolate both to find the temperature after a further five minutes. Students repeat the experiment using different cups, or different volumes of water, or investigate the effect of insulation on the rates of cooling. |

**Assessment options : **Digital technology could be used to create the tables or plot the raw data. |

**Teacher notes : **Be aware of the safety implications of this task. Students will be working with hot water. |