# Question #c9625

##### 1 Answer

618lbforce

#### Explanation:

The size of the pool is unimportant, as long as it can hold the cube. Only the depth matters, because this determines the pressure (=force per unit area).

*It's a pity this problem was stated in old english measures.
I'll convert to metrical units, and convert the answer back.*

The pressure goes up by

(

**Top of the cube**

Is at

this gives a pressure of

Multiply by area:

**The sides**

Since pressure rises linearly with depth, we may use the average pressure which will occur halfway up the cube.

Depth halfway is

Pressure will be

Multiply by area:

**Answer**

**Conversion:**