If this sounds cynical, it is not difficult to set up a simple experiment.
I did this simple but effective experiment many times over several days.
Teachers are shown how to carry out many simple experiments.
They did the simple experiment and of course found that he was not!
Then, with a simple experiment, they can probably figure out the rolling/sliding part themselves.
To help illustrate the difference, let me suggest a simple experiment.
Andrew, think of a simple experiment to test it yourself.
I made a simple experiment which seems to me conclusive.
The best way to explain this is to make a simple experiment.
The group turned to leave, and Cranston, the last to go, tried a simple experiment.