Text Book Maths Problem - 11

Question

Two boats (A and B) leave a harbour simultaneously. Boat A sails on a course of 010 degrees at a speed of 15 knots, while boat B sails on a course of 110 degrees at a speed of 10 knots.

 

If one knot equals 1852 metres per hour, calculate to the nearest kilometre how far the boats will be apart after 3 hours.

Answer 1

triangle with sides 45 and 30

with angle 80 degrees

d= sqr(45^2+30^2 -2(45)(30)Cos80

=sqr(2925 +2700Cos80)

= about 58.25675995 meters

= about 0.583 km apart

= about 1 km apart