In this experiment, the independent variable is light intensity, the dependent variable is the height of the tomato plants, and time (weeks) is a controlled variable.
The independent variable in this experiment is the light intensity given to the tomato plants, as it is the factor being deliberately changed and manipulated by the scientist. The dependent variable would be the height of the tomato plants, as it is the outcome that is being measured in response to the changes in light intensities. Time (weeks) would be considered a controlled variable in this experiment, as it remains constant while the light intensity varies.