tag:techtv.mit.edu,:Array/219744720 2008-09-02 10:20:19 -0400 MIT Department of Physics Technical Services Group <p>A stuffed monkey is suspended from a rod at one end of a lecture hall by an electromagnet. A golf ball gun aimed directly at the monkey cuts power to the electromagnet when fired. Thus, the monkey begins falling at the same instant the gun fires the golf ball. The projectile and target meet in mid air.</p><p>Intuitively one might think that the ball will go over the monkey's head due to its fast speed. However, gravity accelerates all objects downward at the same rate, meaning the monkey and the ball will meet at exactly the same point. If the ball was shot even faster, it would still hit the monkey, but higher above the ground. </p><p>No animals were harmed in this demo. </p> 77 tag:techtv.mit.edu,:Array/219723940 2008-09-02 15:54:18 -0400 MIT Department of Physics Technical Services Group A ball is dropped in front of a meter stick and lit by a strobe light. A long exposure photograph captures the position of the ball at each evenly spaced flash of light. The acceleration of the ball can then be measured from the photo. <br><br> Note that the frame rate of the video capture (30fps) is quite close to the strobe rate (15Hz). This is why the strobe flashes in the slow motion video don't appear to be exactly evenly timed. <br><br> See the <a href="http://www.flickr.com/photos/physicsdemos/3174207211">final image</a> on Flickr. 42 tag:techtv.mit.edu,:Array/219705040 2008-10-28 11:05:41 -0400 wrenow DYNAMICS - Gravitational Forces A Cavendish balance apparatus is used for the experimental verification of Newton's law of universal gravitation. This video shows a time lapse of the position of a laser beam which is reflected off of a mirror attached to a torsional balance which is set to oscillating by a change in position of two lead balls from equilibrium. The apparatus is arranged to ensure that the gravitational force of the lead balls dominates. http://18.74.1.138/~bil/DemoPage/B/B5/B5.htm http://books.google.com/books?id=O58mAAAAMAAJ&pg=PA59 http://en.wikipedia.org/wiki/Cavendish_experiment 22 tag:techtv.mit.edu,:Array/219684240 2008-10-21 11:04:51 -0400 MIT Department of Physics Technical Services Group A CO2 fire extinguisher is mounted on the back of a tricycle. When the CO2 is released, the tricycle is propelled forward. Watch Professor Lewin perform this demonstration on the Martha Stewart Show: <a href="http://www.marthastewart.com/show/the-martha-stewart-show/teacher-appreciation-day?lnc=4ef2dc5bfca40110VgnVCM1000003d370a0aRCRD&amp;rsc=showarchive_tv_show-archive">http://www.marthastewart.com/show/the-martha-stewart-show/teacher-appreciation-day?lnc=4ef2dc5bfca40110VgnVCM1000003d370a0aRCRD&amp;rsc=showarchive_tv_show-archive </a> 53 tag:techtv.mit.edu,:Array/219665340 2008-12-17 16:20:25 -0500 MIT Alumni Association Opening remarks and alumni activities report by Toni Schuman '58, president, MIT Alumni Association; Alumni Fund update presented by Donald E. Shobrys '75, chair, Alumni Fund Board; Campaign for Students update presented by Jeffrey Newton, vice president, Resource Development. 2947 tag:techtv.mit.edu,:Array/219644560 2009-08-20 10:57:46 -0400 MIT Department of Physics Technical Services Group A sand-carrying cart on a track leaves a trail of sand when it travels over a rotating table. This demonstrates the Coriolis Effect. <br><br> For more, watch <a href="http://techtv.mit.edu/videos/3714-the-coriolis-effect">The Coriolis Effect</a>. 74