Answer
Speed doesnt change
Work Step by Step
The total energy of snowball respect to the ground initially will be: $E_{tot}=E_{k0}+E_{p0}=\dfrac {mv^{2}_{0}}{2}+mgh(1)$ Total energy of snowball is conserved so when it hits the ground lets write total energy of snowball respect to ground again : $ E_{tot}=E_{kB}+E_{pB}=\dfrac {mv^{2}_{B}}{2}+0\left( 2\right) $ so from (1) and (2) we get: $v_{B}=\sqrt {v^{2}_{0}+2gh}\left( 3\right) $ So when we look at equation (3) we see the speed doesnt depent on initial angle of snowball but rather depends on magnitute of initial speed and the height of building So if we throw snowball at an angle $α=-41^{0}$ instead of $α=+41^{0}$ the speed of snowball when it reaches the ground will not change.
