`Strings and SpringsMichael McIntosh               Whitney Young Magnet High School                               211 S. Laflin St.                               Chicago IL 60607                               (312) 534-7539Objective:By measuring several periodic phenomena, the student will make graphs and determine what the different shapes indicate.Materials:Two springsTwo strings slightly longer than 1 m120 washersFour stopwatchesStrategy:The activities will be in four separate stations.  The students will divide into groups of four or five and circulate through the stations.Station 1 The Bouncy SpringHang the spring vertically.  Hang 10 washers from the spring.  Lift the washers slightly and let them go.  Measure the time for 20 bounces.  Record the data in a table.  Repeat with 20, 30, 40, and 50 washers.  Make a graph of the data. Station 2 The Stretchy SpringHang the spring vertically and notice the position of the end.  Hang 5 washers from the spring and measure how far it stretched.  Record the data in a table. Repeat with 10, 15, 20, and 25 washers.  Make a graph of the data.Station 3 Mass and TimeHang a string so that it is 1 m long.  Attach 5 washers to the end of the string.  Pull the washers to to side slightly and let them go.  Measure the time for 20 swings.  Record the data in a table.  Repeat with 10, 15, 20, and 25 washers.  Make a graph of the data.Station 4 Length and TimeHang a string and make loops at 20 cm, 40 cm, 60 cm, 80 cm, and 100 cm from the top.  Hang 15 washers from the first loop.  Pull the washers to the side slightly and let them go.  Measure the time for 20 swings.  Record the data in a table.  Repeat for the other loops.  Make a graph of the data. Performance Assessment:Given pictures of several differently shaped graphs, determine which graph matches which station.`