tag:techtv.mit.edu,:Array/218341200 2008-07-24 01:36:17 -0400 Scot Frank Video taken during a summer 2008 trip by Catlin Powers and Scot Frank to Ladakh, India and Yunnan, China. Detailed within are some aspects of rural life, the terain, modes of transportation, people, and culture. This trip was related to field research into suitable areas for more portable and light weight solar cooker and heating system for the Himalayan region. In association with <a href="http://www.oneearthdesigns.org" target="_blank">One Earth Designs</a>, a non-profit focusing on engineering solutions for high-altitude community innovation. 458 tag:techtv.mit.edu,:Array/218316500 2008-10-10 14:24:44 -0400 MIT Department of Physics Technical Services Group Two carts are connected together on an air track with a spring. Under bright lights you can see the coupled oscillation of the carts back and forth, but under black lights you can see that the center of mass moves at a constant velocity. 103 tag:techtv.mit.edu,:Array/218289660 2009-06-01 15:48:40 -0400 MIT Department of Physics Technical Services Group Two or more air carts are connected by springs on an air track. When this system is at resonant frequency, symmetrical patterns called <a href="http://en.wikipedia.org/wiki/Normal_mode">normal modes</a> appear. The normal modes are shown in both undriven and driven cases. In the undriven examples, the normal modes are found by placing the carts at certain distances from each other and then letting them oscillate. In the driven examples they are found by driving the system with a motor, and varying the frequency until the normal mode patterns appear. Both of these methods are shown for systems of two, three, and five coupled carts. 459 tag:techtv.mit.edu,:Array/218270740 2009-06-10 14:04:53 -0400 MIT Department of Physics Technical Services Group Two pucks of the same mass are slid at each other on an air table, and their resulting collisions demonstrate conservation of momentum. Notice on the first collision, for example, that when a moving puck hits a stationary puck dead-on, that the second puck leaves with the same velocity as the first, and the first puck stops moving completely. 80 tag:techtv.mit.edu,:Array/218248140 2009-06-11 14:02:02 -0400 MIT Department of Physics Technical Services Group An air puck is attached to a string that passes through the center of an air table. A weight is attached to the end of the string. The ball is set into rotation in a horizontal circle. When the weight is released, creating a constant force inwards, the radius of the path is shortened and the puck speeds up. A similar effect is seen when the string wraps around a center rod like a tether ball. This creates an increasing force, which causes the puck to inspiral more quickly. 181