6. [-/0.03 Points] DETAILS MY NOTE Distance Between Two Cruise Ships Two cruise ships leave port at the same time. Ship A sails north at a speed of 50 mph while Ship B sails east at a speed of 60 mph. (a) Find an expression in terms of the time t (in hours) giving the distance between the two cruise ships. D : (b) Using the expression obtained in part (a), find the distance between the two cruise ships 5 hr after leaving port. (Round your answer to two decimal places.) mi 7. [-/0.03 Points] DETAILS MY NOTE Distance Between Two Cargo Ships Ship A leaves port sailing north at a speed of 15 mph. A half hour later, Ship B leaves the same port sailing east at a speed of 35 mph. Let t (in hours) denote the time ship B has been at sea. (a) Find an expression in terms of t giving the distance D between the two cargo ships. D(t) = (b) Use the expression obtained in part (a) to find the distance (in miles) between the two cargo ships 2 hr after Ship A has left port. (Round your answer two decimal places.) mi