🔍 Key Concepts

• Relationship between speed and fuel consumption for displacement vessels • How fuel consumption typically relates to speed cubed (Speed³) at sea • Proportion method: using ratios to scale consumption from one speed to another

💭 Think About

• If fuel consumption is roughly proportional to the cube of the speed, how can you write an equation that relates the known condition (178 bbl/day at 13.5 knots) to the unknown condition at 15.0 knots? • Once you have the ratio of the new speed to the old speed, what do you need to do with that ratio (square it, cube it, or something else) to estimate the new fuel consumption? • After you calculate the new fuel consumption, which of the choices is closest to your calculated value?

✅ Before You Answer

• Be sure you are using consistent units (both speeds in knots, same time period of 1 day). • Double-check that you applied the exponent correctly to the speed ratio before multiplying by 178 bbl/day. • Estimate roughly: since speed is increasing from 13.5 to 15.0 knots, fuel use must increase, so you can eliminate any answer that is less than 178 bbls/day.