Question

students swung three pendulums of different lengths back and forth ten times and recorded the finish times of each. view the sample data below.

length of pendulum	trial 1	trial 2	trial 3	average time of swing
medium	9.30 sec	9.50 sec	10 sec	9.60 sec
large	12.00 sec	13.44 sec	14 sec	13.1 sec

which of the following describes the \type of string\ used in the experiment?

• control group
• control (constant) variable
• test (independent) variable
• outcome (dependent) variable

Explanation:

In an experiment, controlled (constant) variables are factors kept unchanged to ensure validity. The "type of string" is not manipulated (independent) or measured (dependent), nor is it a control group. It is held constant.

Answer:

Control (constant) variable