Answer to Question #156719 in Physics for Chilled

Question

 A student is investigating whether using a lid reduces the time taken to heat a beaker of water to

boiling point.

The student can use the following apparatus:

thermometer

250 cm3 glass beaker

250 cm3 measuring cylinder heatproof mat

lid to fit the beaker

clamp, boss and stand.

Plan an experiment to investigate whether using a lid reduces the heating time. You are not required to carry out this experiment.

You should

• list the additional apparatus that you would require

• explain briefly how you would carry out the investigation

• state the key variables that you would control

• draw a table with column headings, to show how you would display your readings; you are not required to enter any readings in the table

• explain how you would use your readings to reach a conclusion.

A diagram is not required but you may draw a diagram if it helps your explanation

Answer 1

The additional equipment is a stopwatch and infrared thermometer.

I suggest conducting two experiments, one with closing the beaker with a known mass of water inside, and the second one with the beaker left open filled with the same mass of water. The initial temperature of water must be equal in both experiments.

Then I would start heating the water (in both experiments) and measuring the temperature every 2 minutes. The table may look like the one below:

If the temperature of the beaker with lid grows faster than the temperature in the open beaker, the lid indeed reduces the time taken to heat a beaker of water to

boiling point.