The speed should be such that it takes 30 seconds to a minute to move the entire length of the rock-slide. Next try pulling the rock or brick along with the winch. The distance between the winch and the rock-slide should be adjusted so that the shock cord does not begin to wind onto to winch this maintains a constant elastic component during the entire travel of the rock or brick. #5th grade physics science fair projects software#Adjust the display software so that the trace is scrolling on the screen and a slight tap on the table is clearly registered. In fact, it is better to have it a few feet away so that it is clear that the vibrations from the sliding rock must travel some distance along the tabletop to reach the sensor. The geophone does not have to be on or right next to the rock-slide. Set up the geophone and display computer on the table with the rock-slide. Secure one end of the 15" piece of elastic shock cord to the winch cord and the other to the dangling end of the cord attached to the brick or rock. Wind the rest of the non-elastic cord onto the winch. Securely attach a loop of non-elastic cord to the rock or brick, leaving an open loop on one dangling end of the cord. The use of two tables prevents the winch from vibrating the table on which the geophone is located. Using the C-clamps, secure the winch to one table and the rock-slide to an adjacent table. Feed one end of the non-elastic cord through this hole and tie a knot in the end so that the cord will be securely attached to the pipe. Drill a 1/4" diameter hole through one side of the 7" section of PVC pipe. Glue a straight PVC junction to the end of the 7"-long pipe to keep it from sliding out of the winch. If the pipe does not slide easily in the holes, use a round file to enlarge the holes. Then slide the 7"-long pipe through the two holes in the winch. Using PVC cement, attach the three pieces of PVC together using the two 90-degree junctions, as indicated. The extra length on the base is to allow more room for clamping the winch to a table. Using the four 2 1/2" wood screws, attach the sides of the winch to the 2"x4" base. The center of the holes should be 1 3/4" from the 6" edge of the wood, as indicated in the sketch below. Using 1 1/4" screws, attach the sides and stop to the rock-slide base, as indicated in the diagram below.ĭrill a 1" diameter hole in each of the 1"圆" boards. #5th grade physics science fair projects serial#This unit attaches to a PC serial port and includes software for MS Windows that will display the seismic data in real time. He can be contacted at to digital converter (AD) and display software: The least expensive AD unit that I have been able to find is Dataq's DI-150-SP, which sells for $100. has a number of used exploration geophones that he is willing to provide to teachers for the cost of shipping. For example: All Electronics Corporation, (800) 826-5432,, currently (November 1998) sells their catalog number GP-1 geophone for $8. Geophone: A small 8 to 14 Hz vertical exploration geophone may be purchased from some surplus stores. Three C-clamps: One to clamp the winch to one table and two to clamp the rock-slide to another table.ġ 13" length of 3/4" PVC pipe, cut into 3 pieces with lengths of 7", 3", and 3" Rough sand paper to cover base of rock or brick: may be required to get best sliding properties. Read through this and the Setup and Operation sections before purchasing any equipment, as some trouble-shooting alternatives are offered.Įlastic shock cord: 15" long by 1/4" diameter Exclusive of the personal computer, the total cost is between $125 and $150. Included are suggested sources for the vibration sensor (geophone) and the computer interface. This process is called elastic rebound.ĭetailed instructions are given for assembly and construction of this demonstration. As the deformation increases, stress also increases, until fault slippage releases the stored elastic energy. In tectonically active regions, the Earth's outer brittle shell, which is about 50 km thick, is slowly deformed elastically along active faults. This intermittent sliding motion mimics the intermittent fault slippage that characterizes the earthquake fault zones. A small vibration sensor, attached to a computer display, graphically monitors this intermittent motion. Although pulled with a constant velocity, the heavy object repeatedly slides and then stops. The apparatus consists of a heavy object that is dragged steadily with an elastic cord. Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Geological Survey (USGS) editorial standards. This report is preliminary and has not been edited or reviewed for conformity with U.S. Geological Survey Open-File Report 98-767, On-Line Edition, Updated March 6, 2001Ī Demonstration of Seismology for Teachers and Students that can be used to Augment Lessons in:įorms of Energy, Elasticity, Friction, Magnetism, Waves
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