Suppose a ship is sailing at a rate of 20 km/h parellel to a straight shoreline. The ship is 8 km from shore when it passes a lighthouse at 1 pm.
a) Let h be the distance between the lighthouse and the ship. Let d be the distance from the ship has travelled since 1 pm. Express h as a function of d. Please include a diagram.
b) Express d as a function of t, the time elapsed since 1 pm.
c) Find hod. What does this function represent?
a) The distance ( in km ) that the ship is from the lighthouse at any time after 1 PM is given by :
h (d) = √ [ 8^2 + (d)^2 ] where d is the distance ( in km ) the ship has traveled since 1 PM
b ) d(t) = 20t where t is the time (in hours) since 1PM
c) h° d = h[d(t) ] = √ [ 8^2 + (20t)^2 ] which represents the total distance (in km) the ship is from the lighthouse at any time t (in hours) after 1PM