Carl Mungan asked some questions about my "hitting the penny"
demonstration/experiment.
Our 1-inch steel balls are going way faster than 20 cm/s. If a ball
rolls off a 36" lab bench at 20 cm/s it is going to hit the floor about
9 cm outward from the edge of the table. * Boring! *
We typically have the ball going 150 to 200 cm/s as it leaves the 36"
high table. That puts the ball out about 60 to 90 cm from the end of
the table when it hits the penny. * Impressive! *
The edge of the table does not matter. We do sometimes have the ball
roll on the table, but we prefer to let the two-rail track extend to the
end of the table because it more precisely contrains the left/right
position. Our track starts out going downhill, then makes a fairly
smooth bend as it becomes horizontal. The horizontal section is about 1
m long, and that is where we measure the velocity. The slanted part is
also one meter and is elevated 0.2 to 0.5 m.
Michael D. Edmiston, Ph.D.
Professor of Physics and Chemistry
Bluffton University
Bluffton, OH 45817
(419)-358-3270
edmiston@bluffton.edu
_______________________________________________
Phys-L mailing list
Phys-L@electron.physics.buffalo.edu https://www.physics.buffalo.edu/mailman/listinfo/phys-l