A student walks east 100 meters in 2 minutes. She
then walks north 200 meters in 4 minutes. Which
statement is true? (1 point)
Her velocity is constant because her speed is
constant.
Her velocity changes because her direction
changes.
Her velocity is constant because her direction is
constant.
Her velocity changes because her speed varies.
The statement that is true is: Her velocity changes because her direction changes.
Her velocity changes because her direction changes.
To determine which statement is true, we need to understand the concepts of speed and velocity.
Speed refers to how fast an object is moving, regardless of its direction. It is calculated by dividing the distance traveled by the time taken. In this case, the student walks east for 100 meters in 2 minutes, resulting in a speed of 100 meters / 2 minutes = 50 meters per minute. She then walks north for 200 meters in 4 minutes, giving us a speed of 200 meters / 4 minutes = 50 meters per minute. Therefore, her speed remains constant at 50 meters per minute.
Velocity, on the other hand, includes both the speed and direction of an object's motion. It is a vector quantity, meaning it has both magnitude (speed) and direction. So, to determine if the student's velocity changes or remains constant, we need to examine the direction of her motion.
The student walks east for 100 meters and then north for 200 meters. Since these two directions are perpendicular to each other, her velocity changes because her direction changes. In other words, she is initially moving in one direction (east) and then changes her direction to another (north). Therefore, the correct statement is: "Her velocity changes because her direction changes."