A ferry is crossing a river. If the ferry is heading north with a speed of 2.5 m / s in relation to the water and the speed of the river is 3.0 m / s to the east, what will the speed of the ship be in relation to the Earth?

The path of a satellite orbiting the earth causes it to pass directly over two tracking stations a and b, which are 51 miles apart. when the satellite is on one side of the two stations, the angles of elevation at a and b are measured to be 87 degrees and 84 degrees, respectively. (a) how far is the satellite from station a? (b) how high is the satellite above the ground?