1. Motion Problems(wind/water) Review Homework 191 #24 195 #40 197 # 46

2. 24. A plane can fly 300 miles downwind in the same time as it can travel 210 miles upwind. Find the speed of the wind if the plane can fly 225 mph in still air. Speed still air +/- wind TimeDistance Downwind225 + w300 Upwind225 - w210 Speed = speed of the plane in still air plus the speed of the wind for downwind speed of the plane in still air minus the speed of the wind for upwind Time = distance divided by speed

4. 40. A cargo ship traveling with the current traveled 180 miles in 9 hours. On its return voyage traveling against the current, it took 18 hours to travel the same distance. The speed of the current is 5 mph. Find the speed of the cargo ship. Speed still air +/- water TimeDistance With the current(water) X + 59(x+5)=180 Against the current X - 518(x-5)=180 EITHER 9(x+5) = 18(x-5) or solve one of the two distance equations X=15 the speed of the cargo ship is 15 mph

5. 46. A boat travels for three hours with a current of 3 mph and then returns the same distance against the current in four hours. What is the boat's speed in calm water? How far did the boat travel one way? Speed still air +/- water TimeDistance With the current(water) X + 33(x+3) Against the current X - 34(x-3) 3(x+3)=4(x-3) 3x+9 = 4x -12 X = 21 speed of the boat is 21 mph Distance 3(21+3) or 4(21-3) = 72 miles