ASVAB Practice Test

Why are metal hoops closer together near the bottom of a wooden water tank?

1. The wood is weaker at the bottom

2. The hoops reduce inward water flow

3. The tank is wider at the bottom

4. Water pressure is greater near the bottom

The correct answer is: The wood is weaker at the bottom

The correct answer is that water pressure is greater near the bottom. In a wooden water tank, the pressure exerted by the water increases with depth due to the weight of the water above. Consequently, the metal hoops are placed closer together at the bottom to provide additional support and prevent the tank from bulging or collapsing under the increased pressure. At greater depths, the water creates a higher pressure that the tank must withstand, which necessitates the reinforcement from the hoops. This design principle ensures the structural integrity of the tank throughout its height, as the material must counteract the forces acting upon it due to the water. While it is true that wood may have varying strength characteristics, it is not solely that the wood is weaker at the bottom but rather that the additional support from the hoops is required to manage the higher pressure. The other options do not accurately address the structural considerations related to water pressure in this context.