An experiment was devised to investigate the effects on the temperature of a cup of coffee when cream is added at different time intervals. Hot and cold water were used instead of coffee and cream. First, a container of water heated to 80°C was allowed to sit for 15 minutes. Its temperature was measured at regular intervals. Next, similar temperature measurements were taken for 15 minutes on a new container of heated water, but this time some cold water was added after the 2-minute reading. Finally, the procedure was repeated except that for this last test, the cold water was added after the 12-minute reading. The resulting recorded temperatures were plotted on the graph shown here.

1. What question was asked in the experiment?

2. What was the hypothesis, expressed as an if-then statement?

3. What were the independent and dependent variables?

4. What was the control in the experiment?

5. There is one thing that is wrong about this graph. What is it?

An experiment was devised to investigate the effects on the temperature of a cup of coffee when cream is added at different time intervals. Hot and cold water were used instead of coffee and cream. First, a container of water heated to 80°C was allowed to sit for 15 minutes. Its temperature was measured at regular intervals. Next, similar temperature measurements were taken for 15 minutes on a new container of heated water, but this time some cold water was added after the 2-minute reading. Finally, the procedure was repeated except that for this last test, the cold water was added after the 12-minute reading. The resulting recorded temperatures were plotted on the graph shown here.

Answers:

1. If you have cool water then you have to add it to the hot water after a few minutes.

2. The independant variable is the cold water

3. The dependant variable is the temperature

4. The control is the hot water without the cold water.

5. The 2 min cold water drops way to much.