Answer:
Assuming h as the height of the cylindrical tank
![F=480\pi h \,g\,\, (lb)/(ft)](https://img.qammunity.org/2020/formulas/physics/college/ugh3nxcvklwhdpzf4chy30xkq35o3qth9q.png)
Step-by-step explanation:
Assuming that the height is
we can find the volume of the cylindrical tank, then:
![V=\pi*r^2*h](https://img.qammunity.org/2020/formulas/physics/college/ejvdj1jizt8caypfsx36jipvp1oj8fdfqf.png)
The diameter is 8.00 ft then
the total volume of the tank is:
![V=\pi (4.00 ft)^2 h=16\pi h\,\, ft^2](https://img.qammunity.org/2020/formulas/physics/college/ixadpz22fpuk0m2m0zuzo6x73l9wyd3b5v.png)
But the tank is half full of oil, then we need half of the volume. For that reason the volume of oil is:
![V_(oil)=(16\pi h)/(2)ft^2=8\pi h \,\,ft^2](https://img.qammunity.org/2020/formulas/physics/college/jyc7imkz13ojgtjsilw80b2sommy536q3w.png)
We know the density of the oil
, with this we can fing the mass of oil that we have because:
then
![m=\rho V](https://img.qammunity.org/2020/formulas/physics/college/o6z8jtbcs38wvelxnwe553dx5zswcv0knw.png)
Then the mass of oil that we have is:
![m=(60.0(lb)/(ft^3))(8\pi h\,\,ft^2)](https://img.qammunity.org/2020/formulas/physics/college/add1fkfqdwifro6o9hredjerynqpvyg8se.png)
![m=480\pi h (lb)/(ft)](https://img.qammunity.org/2020/formulas/physics/college/2u68tu8qdtk182k0vyyk2m9adfxzsk932k.png)
Note that with the value of h we have the mass in correct units.
Finally to find the force we now that
then we just need to multiply the mass by the gravity.
![F=480\pi h \,g\,\, (lb)/(ft)](https://img.qammunity.org/2020/formulas/physics/college/ugh3nxcvklwhdpzf4chy30xkq35o3qth9q.png)