A helium balloon rises vertically at 3.5m/s as the wind carries it horizontally at 5.0m/s.
What is the resultant velocity of the balloon?
apply vector addition forming a right angle triangle and finding the resultant (hypotenuse) using pythagoras theorem..
3.5^2 + 5^2 = y^2
12.5 + 25 = y^2
y = sqrt(37.25)
= 6.10m/s
hope that helps...