What is dimensional analysis? How is it used?

dimensional analysis is the way of converting different units. when you add two physical quantities or equate them they must be in same units.

uses:

to check the correctness of a physical formula

to convert the value from the one system to another.

to form a relationship between different physical quantities

1A: The legs can be a adjusted, as well as the sand can be swapped out. It’s a very good design for running multiple tests.
1B: He could add books or something under the front or back legs in order to increase/decrease the incline, therefore imitating the hypothesis.
1C: He can change out the sand grains to finer ones, or coarser ones, and record his results of each test.
2: If he sets the model at a steep incline and tests it with coarse sand and fine sand, seeing which one makes a narrower, deeper hole.