Ok...so I tried this but Im not getting the solution

Problem: A semicircular plate 2 ft in diameter sticks straight down into freshwater with the diameter along the surface. Find the force exerted by the water on one side of the plate.

F = w h bar Area of the plate

F = (62.4) (0+1/2) 1/2(pi)(1)^2

F = 49 lbs but the answer is 416 lb. What's wrong?