Now we can solvethe problemby substituting into the originalequation:
Hence
and by substitution,
LessonSummary
- We learnedto solveproblemsthat involvedrelatedrates.
Reviewquestions
- a. Makeup a relatedratesproblemaboutthe area of a rectangle.
b. Illustratethe solutionto your problem. - Supposethat a particleis movingalongthe curve Whenit reachesthe point
the -coordinateis increasingat a rate of ft/sec.At what rate is the -coordinatechangingat that instant? - A regulationsoftballdiamondis a squarewith eachside of length ft. Supposea playeris runningfrom
first baseto secondbaseat a speedof ft/sec.At whatrate is the distancebetweenthe runnerand home
platechangingwhenthe runneris of the way from first to secondbase? - At a recentHot Air Balloonfestival,a hot air balloonwas released.Uponreachinga heightof ft, it
was risingat a rate of ft/sec.Mr. Smithwas ft awayfrom the launchsite watchingthe balloon.At
whatrate was the distancebetweenMr. Smithand the balloonchangingat that instant? - Two trainsleft the St. Louistrain stationin the late morning.The first train was travelingEast at a constant
speedof mph.The secondtrain traveledSouthat a constantspeedof mph.At PM, the first train
had traveleda distanceof mileswhilethe secondtrain had traveleda distanceof miles.How fast
was the distancebetweenthe two trainschangingat that time? - Supposethat a ft ladderis slidingdowna wall at a rate of ft/sec.At whatrate is the bottomof the
laddermovingwhenthe top is ft from the ground?