To determine the average velocity of the car that travels 150 kilometers to the north in 2 hours, we need to follow a systematic approach. Let's break it down step-by-step. ### Step 1: Understanding Average Velocity Average velocity is defined as the total displacement divided by the total time taken. Displacement is a vector quantity that refers to the change in position of an object, taking into account the direction of travel. ### Step 2: Identify the Given Information - **Distance traveled**: 150 kilometers (to the north) - **Time taken**: 2 hours ### Step 3: Calculate Displacement Since the car travels in a straight line to the north, the displacement is equal to the distance traveled: - **Displacement** = 150 kilometers north ### Step 4: Calculate Average Velocity The formula for average velocity (\( v_{avg} \)) is: \[ v_{avg} = \frac{\text{Displacement}}{\text{Time}} \] Substituting the values we have: \[ v_{avg} = \frac{150 \text{ km north}}{2 \text{ hours}} = 75 \text{ km/h north} \] ### Step 5: Final Answer The average velocity of the car is **75 km/h north**. ### Step 6: Evaluate the Options Now, let's look at the provided options: - **A. 75 km/h north**: This is the correct answer as it includes both the magnitude and direction of the average velocity. - **B. 75 km/h**: This option is incomplete because it does not specify the direction. Average velocity is a vector quantity and must include direction. - **C. 150 km/h north**: This option incorrectly suggests that the average velocity is equal to the total distance divided by a shorter time. The average velocity is not simply the distance divided by the time taken in this case. - **D. 150 km/h**: Similar to option B, this option fails to include the direction and also misrepresents the average velocity calculation. ### Summary of Why Other Options are Incorrect - **B** lacks direction, making it an incomplete representation of average velocity. - **C** and **D** incorrectly calculate the average velocity, suggesting a misunderstanding of the relationship between distance, time, and velocity. ### Common Pitfalls - Forgetting to include direction when calculating average velocity. - Confusing average speed (a scalar quantity) with average velocity (a vector quantity). - Misapplying the formula by not using displacement instead of total distance when calculating average velocity. ### Revision Summary - Average velocity is calculated as displacement divided by time. - Displacement considers direction; hence, it is important to specify it. - The correct average velocity for the car is **75 km/h north**. - Always ensure to include direction when dealing with vector quantities like velocity.