3. A surface ship is moving (horizontally) in s straight line at 10 km/hr. At the same time, an enemy submarine maintains a position directly below the ship while diving at an angle that is 30 below the horizontal. How fast is the submarine's altitude decreasing? 4. A street light is fastened to the top of a 15-fthight pole. If a 5-ft-tall woman walks away from the pole in a straight line over level ground at a rate of 3 ft/ s, how fast is the length of her shadow changing when she is 10 ft away from the pole