Posted February 28, 2011
Follow the bouncing ball:
This video is visually striking, and regenerative breaking (capturing some of the kinetic energy of a vehicle when slowing down, and reusing that energy later) is a great idea. I do have a problem with their units, though … the mass and speed are given, so we could calculate the kinetic energy of each object, but the video shows Newtons, which are a unit of force, not energy.
Posted February 21, 2011
Light my fire:
I know I take modern safety matches for granted, but this video will give you some idea of the reaction going on in a lit match head. The earliest matches included white phosphorous, which made them dangerous to both users and the workers who made them. Modern matches contain red phosphorous, which is much less hazardous, though MythBusters has shown that 60,000 match heads can make a spectacular fireball.
Posted February 14, 2011
Kinetic vs. potential energy:
Here is an impressive illustration of converting kinetic energy to potential energy. The guy on the ground launches the shovel with enough kinetic energy to just get it to the guy on the scaffold. The shovel is barely moving at the top of the toss, so all the kinetic energy it had at the bottom has been traded for gravitational potential energy at the the top.
Posted February 7, 2011
An old-school "black box":
While modern aircraft flight data recorders are digital, this video shows how it was done before computer chips were so inexpensive and reliable. Airspeed, altitude, heading, and vertical acceleration were recorded as scratches on a metal tape made of an alloy that could survive very high temperatures.
Jacob Clark Blickenstaff is Assistant Professor of Physics and Assistant Director of the Center for Science and Mathematics Education at the University of Southern Mississippi.