Mass = 2kg
distance = 80cm (convert this to meter = 0.8m)
W = fd, right? (At least, from what I remember)
To find Force (or work done) let's use the Force = mass x gravity. Which gives us F = (2.0kg)(9.8m/s^2), giving us N = 19.6N. We must now use the W = fd, which is W = (19.6N)(0.8m) = 15.68J.
I hope that answers your question. Use a calculator to double check, I am a particularly careless person. Teehee.