356 Static Equilibrium and ElasticityP12.15(a)Taking moments about P,RRRsin.cos.....30 0 030 05 0015030 0010392104°+°−===afafafafcmNcmN kNThe force exerted by the hammer on the nail is equal in magnitudeand opposite in direction:. kN at 60 upward and to the right.°(b)fR=°−=sin.30 0 150370NnR==+cos.±±30 0900370900NNsurfaceFijFIG. P12.15P12.16See the free-body diagram at the right.When the plank is on the verge of tipping about point P, thenormal force n1goes to zero. Then, summing torques aboutpoint PgivesτpmgdMgx∑=−+=0orxmMd=FHGIKJ.From the dimensions given on the free-body diagram, observe
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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 .