A student walks east 100 meters in 2 minutes. She then walks north 200 meters in 4 minutes. Which statement is true? (1 point)
A. Her velocity changes because her direction changes.
B. Her velocity changes because her speed varies.
C. Her velocity is constant because her direction is constant.
D. Her velocity is constant because her speed is constant.
The correct answer is A. Her velocity changes because her direction changes. Velocity is a vector quantity that takes into account both the speed and direction of motion. In this scenario, the student changes direction from east to north, indicating a change in velocity.
The correct answer is A. Her velocity changes because her direction changes.
Velocity is a vector quantity that includes both speed and direction. Since the student changes her direction from east to north, her velocity changes.
To determine which statement is true, we need to understand the concepts of velocity, speed, direction, and how they relate to the given situation. Velocity is a vector quantity that includes both the speed and direction of an object's motion.
In the first part of the question, the student walks east 100 meters in 2 minutes. This provides information about the distance and time taken to travel. To determine the student's velocity, we need to consider both speed and direction. The direction is given as east, so the velocity in this part is to the east.
In the second part of the question, the student walks north 200 meters in 4 minutes. Again, we have information about distance and time. The direction is given as north, so the velocity in this part is towards the north.
Now, let's consider the statements:
A. "Her velocity changes because her direction changes." - This is true because when the student changes direction from east to north, the velocity also changes since velocity includes both speed and direction.
B. "Her velocity changes because her speed varies." - This is not true because although we don't have specific information about the speed changing, the velocity changes due to the change in direction, not the change in speed.
C. "Her velocity is constant because her direction is constant." - This is not true because the student changes direction from east to north, causing the velocity to change as well.
D. "Her velocity is constant because her speed is constant." - This is not true because we don't have enough information to determine if the speed is constant or not. Furthermore, the velocity changes due to the change in direction.
Therefore, the correct statement is A. Her velocity changes because her direction changes.