Answer:
![F \approx 3*10^6](https://img.qammunity.org/2022/formulas/physics/college/yyvgdlbin7hpotqqr8tm5vg8dipzqvs9hq.png)
Step-by-step explanation:
From the question we are told that:
Dimension of plate:
![4 m by 8 m](https://img.qammunity.org/2022/formulas/physics/college/r6wmvk5elbm1obaxzarq86rjpxwz4er7f4.png)
Depth submerged
![d=9m](https://img.qammunity.org/2022/formulas/physics/college/3amdan56iaogdok1ppku49aty8mgikx64k.png)
Water density
![\rho=1000 kg/m3](https://img.qammunity.org/2022/formulas/physics/college/hx7nnpgmfrrl1rhkc88z0y62kozdps9hhq.png)
Gravity
![g=9.8m/s^2](https://img.qammunity.org/2022/formulas/physics/college/8dip0evbfvk940umog50dl1h47hbm635ui.png)
Generally the equation for Volume is mathematically given by
![V=L*B*d](https://img.qammunity.org/2022/formulas/physics/college/afktkmpq08f39zp1jpdv74bqez9fboebr8.png)
![V=4*8*9](https://img.qammunity.org/2022/formulas/physics/college/jqxkc8ahvjkcd6avmsqrmlm48zvwhr09oe.png)
![V=288](https://img.qammunity.org/2022/formulas/physics/college/86qzb5chzmkmfftpte94pmjez6akgsm3fi.png)
Therefore The mass of Plate is
![m=\rho*V](https://img.qammunity.org/2022/formulas/physics/college/2jsd58stymesotefkbiopvxcnybtq9xozi.png)
![m=1000*288](https://img.qammunity.org/2022/formulas/physics/college/of568iyo26w2thu1sjgiao0uu0p53dzmli.png)
![m=288000kg](https://img.qammunity.org/2022/formulas/physics/college/gbg7x85gaknos1trieathf55nl6qgfw3zb.png)
Generally the equation for Force on the plate is mathematically given by
F=ma
![F=288000*9.8](https://img.qammunity.org/2022/formulas/physics/college/c9rtncriil2ym2a4sd7ao5ukn0s7uk909x.png)
![F=2822400N](https://img.qammunity.org/2022/formulas/physics/college/re23h2689059zq9tl79ktz1tcvhqhs5ho6.png)
![F=2.8*10^6](https://img.qammunity.org/2022/formulas/physics/college/yiscbtv42cfxlig7ygasuodcqdnzixqgh9.png)
![F \approx 3*10^6](https://img.qammunity.org/2022/formulas/physics/college/yyvgdlbin7hpotqqr8tm5vg8dipzqvs9hq.png)