15. Use the information below to answer the following question(s). Four groups of students were each given a piece of aluminum foil (20 cm 20 cm), a container holding one liter of water, and some pennies. Each group was instructed to use the aluminum foil to make a boat that would hold the greatest number of pennies while floating on the water. The dependent variable in this investigation is the: A. amount of water.
B. number of pennies.
C. size of the aluminum foil.
D. length of the boat.

b

Explanation:

because the variable being tested in this experiment is the number of pennies that could fit into that boat

answer : a model is often used to explain and make things easier to understand when any scientific topic needs to be demonstrated and explained.

as in this case where a scientist wants to use a model to present the results of his detailed scientific investigation. he should do it as it will him to make the audience understand the concept in a much better way. also, it can be changed according to new scientific understandings.