Chapter 8239P8.56k=×250 104. Nm,m=25 0. kgxA=−0100m,UUgxsx====000(a)EKUUAgAsAmech=++EmgxkxAAmech+0122EEmech2mechkgm sm±Nm±mJ JJ+×−+=25 09 800 1001224 512510042....bgejaf(b)Since only conservative forces are involved, the total energy of the child-pogo-stick-Earthsystem at point Cis the same as that at point A.KUUUCgCsCAgA++=++:02509800 0 245125++=−+.kgm sJJ2xCxC=0410m(c)KU U KU UBgBsBAgA:1225 00 0024 51252kgJJvB++=+−+vB=284. ms(d)Kand vare at a maximum when aFm∑0 (i.e., when the magnitude of the upwardspring force equals the magnitude of the downward gravitational force).This occurs at x<0 wherekx mg=orx=×−25 09 8980 1043..kgm sNmm2Thus,KK=maxat xmm(e)UUUUAgxsAsxmax..−
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This note was uploaded on 12/14/2011 for the course PHY 203 taught by Professor Staff during the Fall '11 term at Indiana State University .