Answer
$ 183.75J$
Work Step by Step
İn order to find work done by gravity on snowball, we need to know the final displacement of snowball vertically because gravitational force acts on the ball vertically.
The vertical displacement of snowball is $h=12.5m $ and it is downwards which is in the same direction with gravitational force. So the work done by gravitational force on snowball is:
$W=mg\times h\approx 1.5kg\times 9.8\dfrac {m}{s^{2}}\times 12.5m\approx 183.75J$
