The first controlled, sustained flight in a heavier-than-air craft was made by Orville Wright on December 17, 1903. The plane took off at the end of a rail that was 60 feet long, and landed 12 seconds later, 180 feet away from the beginning of the rail. Assume the rail was essentially at the same height as the ground.
(a) Calculate the average velocity of the plane in feet per second while it was in the air.
(b) What is the average velocity in kilometers per hour? (a) answer in ft/s (b) answer in km/h