To determine the average speed of the car during its journey, 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: \[ v = \frac{150 \text{ km}}{2 \text{ h}} \] 5. **Perform the Calculation**: Now, we perform the division: \[ v = 75 \text{ km/h} \] Thus, the average speed of the car during its journey is **75 km/h**. ### Why Option A is Correct: - **Correct Calculation**: The calculation shows that the average speed is indeed 75 km/h, which matches option A. - **Understanding Average Speed**: Average speed is a straightforward measure of how fast something is moving over a period of time, and in this case, it accurately reflects the car's journey. ### Why the Other Options are Incorrect: - **Option B (150 km/h)**: This option suggests that the car traveled 150 kilometers in just 1 hour. However, since the journey took 2 hours, this option is incorrect. - **Option C (300 km/h)**: This option implies that the car would have traveled 300 kilometers in 1 hour, which is not possible given the distance of 150 kilometers over 2 hours. This is an unrealistic speed for a car. - **Option D (60 km/h)**: This option suggests an average speed of 60 km/h. If we calculate the distance at this speed over 2 hours, it would only cover 120 kilometers (60 km/h × 2 h = 120 km), which is less than the actual distance traveled. Therefore, this option is also incorrect. ### Common Pitfalls: - **Confusing Average Speed with Instantaneous Speed**: Average speed is not the same as instantaneous speed, which can vary at different points during the journey. - **Miscalculating Time or Distance**: Always double-check the values for distance and time to ensure accurate calculations. - **Ignoring Units**: Make sure to keep track of units (kilometers and hours) to avoid confusion in calculations. ### Revision Summary: - Average speed is calculated as total distance divided by total time. - For this problem, the average speed is 75 km/h (Option A). - Other options are incorrect due to miscalculations or unrealistic speeds. - Always verify your calculations and understand the definitions of terms used in physics.