Lab examples with force

if im correct, a force is a push or a pull. what is a lab example having to do with force and please explain. thanks!

Push and pull forces .. (can be horizontal or vertical)
• opening/closing a door - to cause movement against the auto-closer
• lifting a stool (or anything!) - your force has to match a gravitational force
• writing (pushing your pen) - there is some friction between pen-tip and paper (if there wasn't this friction you would find it quite difficult to control the pen's movements