In Exercise 9, what would the distance across the top of the worm thread have to be to make d equal to 0 inches?

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1 Answer
Jan 25, 2018

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When d=0 inches the situation will be represented by the modified figure as shown above. The distance across the top of the worm thread then will be PR

Now PR =2PQ= (2PQ)/(OQ)xxOQ

=>PR = (2PQ)/(OQ)xx(QC+CQ)

=>PR = (2PQ)/(OQ)xx(QC+(CQ)/(CN)xxCN)

=>PR = (2PQ)/(OQ)xx(CN+(CQ)/(CN)xxCN)

=>PR = (2PQ)/(OQ)xxCN(1+(CQ)/(CN))

=>PR = 2tanthetaxx0.75(1+csctheta)

=>PR = 1.5(tantheta+tanthetaxxcsctheta)

=>PR = 1.5(tantheta+sectheta)

=>PR = 1.5(tan15^@+sec15^@)~~1.95 inch