Three sleds are being pulled horizontally on frictionless horizontal ice using horizontal ropes (Fig. 5.48). The pull is horizontal and of magnitude 125 N. Find (a) the acceleration of the system and (b) the tension in ropes A and B.

A

Explanation:

The independent variable in an experiment is the variable that dictates the outcome of the experiment (for example, if the experiment is to determine how much water is required for a plant to grow optimally, then water is the independent variable because the outcome of the experiment (how well the plants grow) is dependent on it).

Hence, in an experiment, the experimenter will test how different inputs will affect the outcome. So therefore, the experimenter will need to change the independent variable, in order to get reliable results.