An engineer is building a bridge that should be able to hold a maximum weight of 1 ton. He builds a model of the bridge that is exactly 4 times smaller than the actual bridge.

16 ounces = 1 pound. 2,000 pounds = 1 ton.

If a test of the model shows that it holds 8,000 ounces, will the bridge hold 1 ton?

8,000 ounces on the model is equal to
ounces on the actual bridge.
Convert ounces to pounds. The actual bridge can hold
pounds.
Therefore, the bridge
hold 1 ton

1 answer

To determine if the actual bridge will hold 1 ton based on the model's performance, let’s go through the calculations step by step.

  1. Convert model's weight capacity from ounces to pounds:

    • The model can hold 8,000 ounces.
    • Since \(16\) ounces = \(1\) pound, we convert ounces to pounds: \[ 8,000 , \text{ounces} \div 16 , \text{ounces/pound} = 500 , \text{pounds} \]
  2. Determine the equivalent weight capacity of the actual bridge:

    • The model is 4 times smaller in size. When scaling, the weight capacity scales with the cube of the size ratio. This is because weight (or mass) is proportional to volume, and volume is a cubic measurement.
    • Therefore, the actual bridge can hold: \[ 500 , \text{pounds} \times 4^3 = 500 , \text{pounds} \times 64 = 32,000 , \text{pounds} \]
  3. Convert pounds to tons:

    • Since \(2,000\) pounds = \(1\) ton, we convert pounds to tons: \[ 32,000 , \text{pounds} \div 2,000 , \text{pounds/ton} = 16 , \text{tons} \]
  4. Conclusion:

    • The actual bridge can hold \(16\) tons.

Thus, based on the findings:

  • The model holds 8,000 ounces, which is equal to 500 pounds on the model.
  • The actual bridge can hold 32,000 pounds, which is equal to 16 tons.

Therefore, the bridge will hold 1 ton.