To find the average velocity of the car over 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, taking into account 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: - The displacement from the starting point after the first leg is +150 km (north). - After the second leg, the car moves 50 km south, which reduces the northward displacement. So, the total displacement can be calculated as: \[ \text{Total Displacement} = 150 \text{ km (north)} - 50 \text{ km (south)} = 100 \text{ km (north)} \] ### Step 3: Calculate Total Time 1. **Time for the First Leg**: 2 hours. 2. **Time for the Second Leg**: 1 hour. Total time taken for the trip 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: \[ \text{Average Velocity} = \frac{100 \text{ km (north)}}{3 \text{ hours}} \approx 33.33 \text{ km/h (north)} \] ### Conclusion: Correct Option The average velocity of the car over the entire trip is approximately **33.33 km/h north**. Therefore, the correct option is: **C. 33.33 km/h north** ### Step 5: Explanation of Other Options - **A. 50 km/h north**: This option is incorrect because it does not take into account the total displacement and time correctly. It seems to be an average of the two distances without considering the direction and total time. - **B. 100 km/h north**: This option is incorrect as it suggests that the car traveled 100 km in 1 hour, which is not the case. The total distance traveled is not the same as the displacement. - **D. 0 km/h**: This option is incorrect because it implies that there was no net movement, which is not true. The car did move northward overall, resulting in a positive displacement. ### Common Pitfalls - Confusing distance with displacement: Remember that distance is a scalar quantity (only magnitude), while displacement is a vector quantity (magnitude and direction). - Not accounting for direction when calculating average velocity. - Miscalculating total time or total displacement. ### Revision Summary - Average velocity = Total displacement / Total time. - Displacement considers direction; total distance does not. - For this problem, total displacement is 100 km north, and total time is 3 hours. - Average velocity is approximately 33.33 km/h north.