To determine the average speed of the car during its trip, we can use the formula for average speed, which is defined as the total distance traveled divided by the total time taken. ### Step-by-Step Explanation: 1. **Identify the Total Distance**: The car travels a total distance of 150 kilometers. 2. **Identify the Total Time**: The time taken for this journey is 2 hours. 3. **Use the Average Speed Formula**: The formula for average speed (v) is given by: \[ v = \frac{\text{Total Distance}}{\text{Total Time}} \] 4. **Substitute the Values**: Plugging in the values we have: \[ v = \frac{150 \text{ km}}{2 \text{ h}} = 75 \text{ km/h} \] 5. **Calculate the Result**: Performing the division: \[ v = 75 \text{ km/h} \] Thus, the average speed of the car during this trip is **75 km/h**. ### Why Option A is Correct: - **Correct Calculation**: The calculation follows the correct formula for average speed, and the values used are accurate. - **Units**: The units are consistent (kilometers and hours), which is essential for calculating speed. ### Why Other Options are Incorrect: - **Option B (150 km/h)**: This option suggests that the car traveled the entire distance in just one hour, which is not the case since it took 2 hours. - **Option C (300 km/h)**: This option implies an unrealistically high speed, suggesting the car would cover 300 kilometers in one hour, which is not supported by the given distance and time. - **Option D (60 km/h)**: This option is also incorrect as it suggests a lower speed than what was calculated. If the car were traveling at 60 km/h for 2 hours, it would only cover 120 kilometers, not the 150 kilometers stated. ### Common Pitfalls: - **Misunderstanding Average Speed**: Some students may confuse average speed with instantaneous speed, which can lead to incorrect calculations. - **Unit Conversion**: Always ensure that the units for distance and time are compatible. In this case, both are in kilometers and hours, which is appropriate for calculating speed in km/h. - **Rounding Errors**: Be careful with rounding numbers during calculations; ensure that you maintain accuracy until the final answer. ### Revision Summary: - Average speed is calculated using the formula: \( v = \frac{\text{Distance}}{\text{Time}} \). - For this problem, the average speed is \( 75 \text{ km/h} \). - Always check that your units are consistent when performing calculations. - Be aware of common misconceptions regarding average versus instantaneous speed.