******************************************************************************* name1: name2: C1: B1: Submit Date: 04/22/2009 Time: 14:33 lastweek: thisweekplan: outsideclass: Equipment: progress: ******************************************************************************* name1: Baggs name2: Jones C1: B1: Submit Date: 04/22/2009 Time: 14:34 lastweek: We breadboard wired the photogate and found that the 555 timer and the PT and the LED were incorrectly wired. On 4/20/09, we fixed the wiring. thisweekplan: This week we will plan on checking our wiring by testing to see whether or not it works with the flash unit, and if it succeeds, we will test the maximum distance between the PT and the LED which will still allow the photogate to work, and then solder the photogate together. We will later set up the photogate, as well as acquire a towel whip so that we may attempt to take a picture of the towel whipping as well as get aiming practice with the whip. Also we will need to experiment with creating an approximate point source for our project. The picture that we plan on taking this week is not intended to be useful in viewing the shockwave, but only fine-tuning our equipment and procedure for taking the photos outsideclass: We already spent some time outside of the lab periods fixing the photogate, and we cannot solder in our rooms, but if there is time when the physics floor is open, we will attempt to solder the photogate together. Equipment: Soldering iron, scrap wire, solder, a cotton sheet, Vivitar 283 flash unit, camera, connectors, progress: So far, we have really only just started, and have encountered a few problems, but we do expect to reach our goal by the end of this week. ******************************************************************************* name1: Jones name2: Baggs C1: B1: Submit Date: 04/27/2009 Time: 14:34 lastweek: We figured building an operational photogate with no delay. We have a laser as a light source such that we have room to whip. We me made the towel we will use to whip. We tested whether whipping the towel through the photogate activated the photogate activated the trigger. (Success). We set up to take a picture of the whip so we could begin to calibrate the camera. thisweekplan: We plan to calibrate the camera such that it captures a clear image of the whip so that have a point to use when we start to calibrate the camera for the shadowgram. We will try to make a point source light that is powerful enough to make a shadowgram. We will possibly make a delay unit so that taking the set-up does not require the photograph to include the photogate. We will find a material to use as the background of the shadowgram. outsideclass: We should use this time to build the delay unit. Equipment: We may need retroreflective material. We may need wires and components to a delay unit or a delay unit. We should verify set-ups using the book by Davidhazy. progress: We finished the photogate and got as far as almost taking a picture. We expect to take a shadowgram of the tip of a whip. Whether probability will allow us to take a picture of the shockwave once set-up is complete is not yet known. ******************************************************************************* name1: Jones name2: C1: B1: Submit Date: 05/04/2009 Time: 15:02 lastweek: We modified our set up to minimize the amount of error in the diffraction of the light by minimizing the distance between our toaster and the background sheet. thisweekplan: We are going to attempt to make a shadowgraph set up for monitoring the heat dispersion from a toaster that we can later apply to the whipping of a towel or other phenomena. outsideclass: We need to investigate what changes can be made to make a more sensitive and accurate set up so that the error created by nonparallel beams of light is not greater than the diffraction of interest. Equipment: We do not anticipate a need for additional materials or equipment. progress: We have taken a picture of a silhouette of a toaster. This is close to what we want in terms of creating a shadowgraph, but considering the amount of heat given off by a toaster, we should be able to see a temperature gradient. ******************************************************************************* name1: Jones name2: Baggs C1: B1: Submit Date: 05/11/2009 Time: 14:35 lastweek: We used a pinhole slide in a projector to create a near point source of light. This was very effective in creating a shadowgraphy set up that allowed us to see the heat rising off of a toaster. thisweekplan: We will take one photo using our projector method, but because we cannot use it for high speed images, we will continue to try to refine our flash unit such that we have collimated light. We will be attaching a lens a focal length away from the source of the flash to focus the light into approximately parallel beams. outsideclass: We will look up the method for measuring the focal length of a lens. We will also contact Dr. Gary Settles periodically to let him know how we are going. Equipment: progress: We have been delayed in getting a high speed shadowgraphy method. As soon as we can finish troubleshooting the method, all that remains is taking pictures. ******************************************************************************* name1: Baggs name2: Jones C1: ON B1: Submit Date: 05/18/2009 Time: 11:38 lastweek: Last week we created a working shadowgraphy method, with which we took a few photos of heat waves coming off of a toaster and a candle. We wrote up our setup for replication. We attempted to use the spot to take photos of these heat waves in preparation for our photography of the whip. thisweekplan: We plan to use the bursting of balloons with our current setup to view high speed shockwaves instead of the initial plan of a whip because we cannot use the spot. outsideclass: We will fill helium balloons, find/make a sound trigger, and we will writeup all necessary parts of the lab report Equipment: because of time constraints we may request the use of a sound trigger if we do not already have one. progress: We do not expect to reach our original goal of studying the shockwaves propagating from a towel whip, but instead we will make a new goal of studying the shockwaves coming off of a balloon burst.