Answer:
<em>a) The variable that we will change will be the different liquids.</em>
<em>b) The variable which will be kept same will be the ramp angle, the time for measuring in each experiment and the heat. </em>
Explanation:
In a scientific experiment, an independent variable is a variable which is changed by the researcher so that its effect on the dependent variable can be studied.
A dependent variable is a variable which is under study and might be influenced by changes in the independent variable.
It is best to study the effect of a single independent variable at a time so that we can easily infer the results.
<u><em>In the scenario discussed in the question, we would change the different liquids so that the time taken by each liquid to flow down the ramp can be studied.</em></u>
<u><em>We will keep the ramp angle, the time (of each experiment) and heat for each of the experiments the same so that a just conclusion can be drawn.</em></u>