Use the tangent to write
tan(25o) = h1 / 300
and
tan(60o) = (h1 + h2) / 300
Solve for h1 and h2
h1 = 300 tan(tan(25o))
and
h1 + h2 = 300 tan(60o)
Use the last two equations to find h2
h2 = 300 [ tan(60o) - tan(25o) ]
If it takes the balloon 2 minutes (10:00 to 10:02) to climb h2, the the upward speed S is given by
S = h2 / 2 minutes
= 300 [ tan(60o) - tan(25o) ] / (2 * 60) = 3.16 m/sec
