I learned that you use more force when something or someone is in the chair, than when the chair is empty.
We placed a person in a rolling chair and pushed them down the hall. Then we pushed the rolling chair empty, and after that we put a forty five pound weight in the rolling chair while someone was in it.
It took more force to push the chair with someone in it and gave it a big acceleration, and less force when the chair was empty and gave it a little acceleration.
