The Plane in the Wind

AN AIRPLANE FLIES in a straight line from airport A to airport B, then back in a
straight line from B to A. It travels with a constant engine speed and there is no
wind. Will its travel time for the same round trip be greater, less or the same if,
throughout both flights, at the same engine speed, a constant wind blows from A
to B?

ANSWER: Since the wind boosts the plane’s speed from A to B and retards it from B to
A, one is tempted to suppose that these forces balance each other so that total
travel time for the combined flights will remain the same. This is not the case,
because the time during which the plane’s speed is boosted is shorter than the
time during which it is retarded, so the over-all effect is one of retardation. The
total travel time in a wind of constant speed and direction, regardless of the
speed or direction, is always greater than if there were no wind.

Enregistrer un commentaire

Plus récente Plus ancienne