A pipeline leak lasts 2.5 hours before it can be stopped. The mass flow rate of the leak is 1.5 kg/s. What is the quantity of the liquid spilled (in kg)?

A pipeline leak lasts 2.5 hours before it can be stopped. The mass flow rate of the leak is 1.5 kg/s. What is the quantity of the liquid spilled (in kg)?

• A. 9000 kg
• B. 13500 kg
• C. 18000 kg
• D. 22500 kg

Answer: (B)

Mass spilled equals the mass flow rate multiplied by the duration. Start by making the time consistent with the flow rate’s units. The leak lasts 2.5 hours, which is 2.5 × 3600 = 9000 seconds. With a flow rate of 1.5 kg per second, the total spilled mass is 1.5 × 9000 = 13,500 kg. Check the units: kg/s times s gives kg, as expected. Another way to see it is converting the flow rate to kilograms per hour (1.5 kg/s × 3600 s/hour = 5400 kg/hour) and multiplying by 2.5 hours to get the same result. The quantity spilled is 13,500 kg.

Mass spilled equals the mass flow rate multiplied by the duration. Start by making the time consistent with the flow rate’s units. The leak lasts 2.5 hours, which is 2.5 × 3600 = 9000 seconds. With a flow rate of 1.5 kg per second, the total spilled mass is 1.5 × 9000 = 13,500 kg. Check the units: kg/s times s gives kg, as expected. Another way to see it is converting the flow rate to kilograms per hour (1.5 kg/s × 3600 s/hour = 5400 kg/hour) and multiplying by 2.5 hours to get the same result. The quantity spilled is 13,500 kg.