3.Elizabeth tested how high five different brands of new tennis balls would bounce when dropped from the same height of 2 meters. She dropped the balls so that they hit the same floor tile each time. In this consumer testing she did not have a control experiment but took factual information from the manufacturers on how well their product bounced (resiliency). She tested 100 balls of each brand. She measured the bounces in centimeters. what is the controlled variable and the Independant variable and the dependent variable

Controlled variable: the height from which the ball is dropped and the floor tile on which the ball hits

Independent variable: different tennis ball brands

Dependent variable: height of bounce in centimeters

Explanation:

Scientific experiments have three major kinds of variables:

Independent variable: This is the variable that is subject to the manipulation of the experimenter. The values of this variable are determined by the experimenter. In this example, Elizabeth determines the brand of tennis ball to be tested, hence the tennis ball brand is the independent variable

Dependent variable: This variable has values which are a result of the effect of the manipulation of the independent variable. The values of the dependent variable are not under the direct control of the experimenter. They are simply the results of the experiment. Here, the height to which the ball bounces is not predetermined, hence it is the outcome or dependent variable.

Control variables; These are variables that can affect the outcome of the results of the experiment but are kept constant throughout the experiment, to rule out biases when testing the effect of the independent variable.