So far, I have tried calculating out the difference if force using two methods (which, honestly are probably the same method): a. Calculating the difference in pressures and b. using buoyancy. I'll spare the details of the first method, but the second method is as follows:
Since the block is stationary, the net force on it is 0. Therefore, it is an accurate statement that $F_N + F_B - mg = 0$.
$F_N = mg - F_B$
$F_N = hA\rho_bg - hA\rho_wg$
$F_N = hAg (\rho_b - \rho_w)$
$F_N = 0.3*0.5*9.8*(6.7*10^3-2.5*10^3)$
$F_N = 0.6174 * 10^4$
Which is obviously not the correct answer, according to the website. (side note, 13.85 was just a random number I entered to get the answer).
So my question is, what is the proper way to do a buoyancy problem like this? Or is there somewhere I'm going wrong?