While steaming at 14 knots, your vessel burns 276 bbls of fuel per day. What will be the rate of fuel consumption if you decrease speed to 11.7 knots?
• Relationship between speed and fuel consumption for displacement vessels (often approximated by a cube law: fuel ∝ speed³) • How to use ratios when you know fuel consumption at one speed and need it at another speed • Careful calculator work: doing the speed ratio first, then applying the power (square or cube)
• If fuel burn at 14 knots is known, how can you express the new fuel burn at 11.7 knots as a multiple or fraction of the original burn? • Should the fuel consumption go up or down when you slow from 14 to 11.7 knots? By a lot or by a little? Estimate first, then calculate. • What mathematical operation do you apply to the speed ratio (new speed / old speed) before multiplying it by 276 bbls/day?
• Compute the speed ratio correctly: 11.7 ÷ 14 (not the other way around). • Apply the correct exponent to the speed ratio before multiplying by 276 bbls/day. • After calculating, check whether your result is less than 276 (it must be, since you reduced speed) and reasonably close to one of the options.
No comments yet
Be the first to share your thoughts!