Two ships are moving along a line due east (see figure below). The trailing vessel has a speed relative to a land-based observation point of v1 = 59.5 km/h, and the leading ship has a speed of v2 = 45.0 km/h relative to the point. The two ships are in a region of the ocean where the current is moving uniformly due west at vcurrent = 13.9 km/h. The trailing ship transmits a sonar signal at a frequency of 1,200.0 Hz through the water. What frequency is monitored by the leading ship?
____Hz