A hot air balloon rises vertically with a speed of 2m/s.?

im going to assume you meant what direction the balloon will go.

change 2 m/s to 7.2 km/hr because there are 3.6 km/h in 1 m/s

use the pythagorean theorem:

2^7.2 + 8^2 = C^2

C=10.76

Then use cosine to find the angle (a):

cos^-1 8/10.76

= 41.97 degrees above the horizontal

Your question makes no sense as it is written. You probably mean to ask what direction above

horizontal the balloon moves.

2m/s should be multiplied by 3600 sec/hour and then divided by 1,000 to get the number of km.

That will give the speed in km/hr, to have the same units as the wind speed.

Then you need to divide the vertical speed by the horizontal wind speed to get a number with no

dimensions. That number will equal the tangent of the angle above horizontal for the total speed

of the balloon. Either use a calculator's inverse tangent function, or look up the arctan of the

calculated number in some math table. I will not give you the answer itself. You will learn nothing

that way.