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Home > PC3 > Chapter 12 > Lesson 12.1.5 > Problem 12-83

12-83.

A boat traveling due north at km/hr is heading directly for a port. The port is exactly km away when the captain sees another boat leave the port traveling due east at km/hr.

  1. Determine the angle (from due north) that the captain of the first boat needs to position their telescope to watch the second boat. Express your answer in terms of , the amount of time since the second boat was due north of the first.

    Draw and label a diagram. Use consistent units.

    Vertical segment, top end point labeled port, segment bracketed & labeled 8, bottom portion of segment is solid ray pointing up, labeled 150, t, rest of segment is dashed & vertical leg of right triangle, solid horizontal leg is ray pointing right, extending from top end point of segment, labeled 120, t, angle opposite horizontal leg labeled, theta.

    Write an equation with and . Use sine, cosine, or tangent.

  2. If the boat that is traveling north wants to catch the boat that is traveling east, what direction will the boat need to head to catch up to the eastbound boat? How long will this take?

    Draw a new diagram. The boat traveling due north will now travel at an angle.

    Dashed Vertical segment, top end point labeled port, segment, labeled 8, is vertical leg of right triangle, horizontal leg is solid ray pointing right, labeled, 120, t, hypotenuse is solid ray, from bottom segment endpoint pointing up & right, labeled  150, t, angle opposite horizontal leg labeled, theta.

    Write equations with and/or . Use sine, cosine, tangent, and/or the Pythagorean Theorem.