1. Drag force F on the boat is jointly proportional to wetted surface area A on hull and square of speed s of boat. A boat experiences the drag force of 220 lb when traveling at 5 mi/h with the wetted surface area of 40 ft2. How fast should the boat be traveling if it has 26 ft2 of wetted surface area and is experiencing the drag force of 200 lb?
2. Stopping distance D of the car after brakes have been applied differs directly as square of speed s. Certain car traveling at 50 mi/h can stop in 215 ft. Determine maximum speed it can be traveling if it requires to stop in 160 ft?
3. State statement as the equation. Use given information to determine constant of proportionality, k. t is jointly proportional to x and y and inversely proportional to r. If x = 4, y = 5, and r = 12, then t = 25.