NEWTON'S 1ST LAW

1F10.20 INERTIA VS WEIGHT
1F20.10 INERTIA AND MASS
1F20.34 INERTIA DEVICE
1F30.10 PERSISTENCE OF MOTION
1F30.20 TABLECLOTH PULL

 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

 1F20.34 Inertia Device Pull back the piece of metal and let go. It will knock the piece of plastic out from under the ball. The ball will fall in the cup.    Setup Requirements: Minimal Equations: Newton's First Law Safety Issues: None

 1F30.10 Persistence of Motion Long track shown in photo was damaged and has been replaced by a different model.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