To determine the average velocity of the car for the entire trip, we need to follow a systematic approach. Let's break it down step-by-step. ### Step 1: Understand the Concept of Average Velocity Average velocity is defined as the total displacement divided by the total time taken. Displacement is the straight-line distance from the starting point to the final position, along with the direction. ### Step 2: Calculate Total Displacement 1. **First Leg of the Trip**: The car travels 150 kilometers north. 2. **Second Leg of the Trip**: The car then travels 50 kilometers south. To find the total displacement: - Starting from the origin (0 km), after the first leg, the car is at +150 km (north). - After the second leg, the car moves south 50 km, which means it moves from +150 km to +100 km (150 km - 50 km = 100 km north). Thus, the total displacement is: \[ \text{Total Displacement} = 100 \text{ km north} \] ### Step 3: Calculate Total Time 1. **Time for the First Leg**: The car travels for 2 hours. 2. **Time for the Second Leg**: The car travels for 1 hour. Total time taken is: \[ \text{Total Time} = 2 \text{ hours} + 1 \text{ hour} = 3 \text{ hours} \] ### Step 4: Calculate Average Velocity Now, we can calculate the average velocity using the formula: \[ \text{Average Velocity} = \frac{\text{Total Displacement}}{\text{Total Time}} \] Substituting the values we found: \[ \text{Average Velocity} = \frac{100 \text{ km north}}{3 \text{ hours}} \] \[ \text{Average Velocity} = 33.33 \text{ km/h north} \] ### Conclusion: Correct Option The average velocity of the car for the entire trip is **33.33 km/h north**, which corresponds to option **C**. ### Step 5: Analyze Other Options - **Option A (50 km/h north)**: This option is incorrect because it does not take into account the total displacement and total time correctly. It seems to suggest a misunderstanding of how average velocity is calculated. - **Option B (40 km/h north)**: This option is also incorrect. It may arise from a miscalculation of either displacement or time, but it does not reflect the actual average velocity calculated. - **Option D (25 km/h south)**: This option is incorrect as it suggests a southward average velocity, which contradicts the net displacement being north. The average velocity must reflect the direction of the total displacement. ### Common Pitfalls - **Confusing Distance with Displacement**: Remember that distance is the total path traveled, while displacement is the straight-line distance in a specific direction. - **Ignoring Direction**: Average velocity is a vector quantity, meaning it has both magnitude and direction. Always include the direction in your final answer. - **Miscalculating Total Time**: Ensure that you add the time for each leg of the trip correctly. ### Revision Summary - Average velocity is calculated as total displacement divided by total time. - Displacement considers the direction of travel, while distance does not. - The average velocity for the car's trip is 33.33 km/h north. - Always check your calculations for both displacement and time to avoid common mistakes.