1F10.20 Inertia vs Weight

Have students come up to front desk and lift and move horizontally what looks like a regular Pepsi can. It is filled with lead so a noticeable force is needed to move it horizontally as well as lift it. Compare to empty can and can filled with Pepsi.

Setup Requirements: Off the shelf .  Another way to do this is to attach scale to can and show difference in force needed to move cans.

Equations: w = mg

Safety Issues: Avoid dropping can filled with lead on fingers or feet.

1F20.10 Inertia & Mass

Demonstrate inertia. If you jerk the bottom string the bottom string should break. If you pull with slowly increasing force top string will break.

Setup Requirements: Connect string to bottom of mass. Connect top of mass to rod using string. Practice before class.

Equations: none

Safety Issues:  weight  hitting hand

1F30.10 Persistence of Motion

Long track shown in photo was damaged and has been replaced by a different model. A short track is also available for use in smaller rooms. Shove a cart so it moves along air track. If adjusted properly cart will go to end without noticeably slowing. Compare with what happens if force of friction present. Early philosophers believed a force had to be present al all times if there was motion.

Setup Requirements: Ask ahead of time. Track needs some time to set up and adjust. May need cleaning.

Equations: F = ma and Newton's 1st Law.

Safety Issues: Hitting things while moving track. Carts are easily damaged enough to cause rubbing on track if fall off track.

1F30.20 Tablecloth Pull

Put cups, saucers, plates, & bottle on tablecloth. Pull hard down and out. If you are lucky the objects will stay on desk.

Setup Requirements: Minimal. Practice before trying it in class.

Equations: Newton's First Law

Safety Issues: Broken glass