Final answer:
When securing chemicals during transportation, the recommended options are sand bags, straps, or blocks. In the case of sandbags used around a levee leak, they balance the hydrostatic pressure by equalizing the height of the water, thereby stopping the flow.
Step-by-step explanation:
To answer the student's question about securing chemicals during transportation, it is recommended to use any of the options listed as each provides a different kind of restraint: sand bags, straps, and blocks. When it comes to the specific context of using sandbags to prevent water from leaking through a levee, the principle behind this is related to hydrostatic pressure, which depends on the height of the water column and not on the total amount of the water.
Sandbags work effectively because they form a barrier that raises the water level on the leak's side to a height where the hydrostatic pressure matches the pressure of the larger body of water. This balance of pressure stops the flow of water under the levee. Inside the column formed by sandbags, the water height is crucial since pressure at a point in a fluid at rest depends only on the vertical depth of the fluid at that point.