P is the starting point for ship B
after 3 hrs (3 PM)
B is north of P by ... 3 * 16 NM
A is west of P by ... [20 + (3 * 24)] NM
APB is a right triangle , hypot AB
BP^2 + AP^2 = AB^2
differentiating
... 2 BP dBP/dt + 2 AP dAP/dt = 2 AB dAB/DT
cancel the 2's , plug in known quantities
At noon, ship A is 20 nautical miles due west of ship B. Ship A is sailing west at 24 knots and ship B is sailing north at 16 knots. How fast (in knots) is the distance between the ships changing at 3 PM? (Note: 1 knot is a speed of 1 nautical mile per hour.)
1 answer