In a distance-time graph, the slope represents which quantity?

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

Answer: (B)

On a distance-time graph, the vertical axis shows distance and the horizontal axis shows time. The slope tells you how fast distance is changing with time, which is speed. A steeper line means a higher speed, a horizontal line means the object isn’t moving (speed zero), and a curved line indicates speed is changing over time (the instantaneous speed at a moment is the slope of the tangent). Velocity would require direction, which this graph doesn’t show, so the slope reflects speed, not velocity. Acceleration relates to how speed changes, which would appear as a changing slope or on a velocity-time graph, while displacement is the overall distance covered, not the rate of change.