Which quantity describes the straight-line change in position between two points?

Which quantity describes the straight-line change in position between two points?

• A. Displacement
• B. Velocity
• C. Momentum
• D. Acceleration

Answer: (A)

Displacement describes the straight-line change in position from where you started to where you ended, including direction. It’s a vector, so it has both magnitude and direction, and it depends only on the initial and final positions, not on the path taken. For example, if you start at a point and end 2 meters directly north, your displacement is 2 meters north, even if you wandered around along the way. Velocity tells you how fast and in what direction that position is changing per unit time, so it’s about the rate of displacement. Momentum is mass times velocity, linking motion to how much “oomph” the object has. Acceleration is how velocity changes over time.

Displacement describes the straight-line change in position from where you started to where you ended, including direction. It’s a vector, so it has both magnitude and direction, and it depends only on the initial and final positions, not on the path taken. For example, if you start at a point and end 2 meters directly north, your displacement is 2 meters north, even if you wandered around along the way.

Velocity tells you how fast and in what direction that position is changing per unit time, so it’s about the rate of displacement. Momentum is mass times velocity, linking motion to how much “oomph” the object has. Acceleration is how velocity changes over time.