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Calculus 12 Physics Question. Bert C hen Nancy Hu Jocelyn Wang John Zhang Serena Wang. # 44.
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Calculus 12Physics Question Bert Chen Nancy Hu Jocelyn Wang John Zhang Serena Wang
# 44 A boat leaves a dock at 2:00 PMand travel due south at a speed of 20km/h. another boat has been heading due east at 15km/h and reaches the same dock at 3:00 PM. At what time were the two boats closest together.
Solution • When the boat leave dock t hours, y is shortest. • 2Y’ =1250t-450 • t=0.36 15km/h Dock 20km/h Y
# 46 A woman at a point A on the shore of a circular lake with radius 2 mi wants to arrive at the point C diametrically opposite A on the other side of the lake in the shortest possible time. She can walk at the rate of 4 mi/h and row a boat at 2 mi/h. How should she proceed?
Solution B • T=+(fomula) • T’=-2+1 • Let’s T’ equal to zero • sin𝜃=0.5 • 𝜃==30 2mi/h 4mi/h A C 4