Precal
posted by Nicholas .
A hotair balloon, headed due east at an average speed of v = 14 miles per hour and at a constant altitude of h = 120 feet, passes over an intersection (see the figure). Find an expression for its distance d (measured in feet) from the intersection t seconds later.

The balloon travels 14mi/hr*t/3600 where t is in seconds. I suppose it would be better to change the velocity to ft/sec
Memorize this conversion factor 60mph=88fps
the balloon travels then 14/60*88 t feet.
the triangle then yields a slant height of
distance= sqrt (120^2+(14*88/60 t)^2 )