Final answer:
To determine how long Mrs. Liu can drive before her car runs out of gas, one needs to analyze the slope of the graph that shows the rate of gasoline consumption, know the total capacity of the tank, and perform a calculation to estimate the remaining driving time assuming constant consumption.
Step-by-step explanation:
The question asks to determine how long Mrs. Liu can drive her car before the gas tank is empty, based on the graph showing the amount of gas left as she drives at a steady speed for 2 hours. To answer this, we need to find the rate at which the gas is being used and then use it to estimate the time until the tank reaches empty.
To find the rate of gasoline consumption, you would typically look at the slope of the graph, which shows the decrease in gas over time. If the graph shows a linear decrease, the slope will give you the rate (e.g., gallons per hour). Suppose the graph indicates that the tank started full and decreased to half over 2 hours. In that case, the consumption rate is half the tank's capacity divided by 2 hours. If you know the total capacity of the tank, you can calculate the driving time until empty.
However, since the actual graph and numerical data are not provided here, we can only guide you through the process hypothetically. With the actual graph, you would:
- Find the slope of the graph (gasoline used per hour).
- Determine the total capacity of the car's gas tank.
- Divide the remaining gasoline by the consumption rate to calculate the remaining driving time.
Remember, this calculation assumes a constant rate of consumption, which may not be accurate in real-life scenarios due to variations in driving conditions and car performances.