A displacement-time graph is curved and concave downward

Solution

The shape of the displacement-time graph reveals information about the nature of motion. If the graph is curved, the motion is non-uniform, and if it is concave downward, this indicates that the slope of the graph (i.e., velocity) is decreasing with time. A decreasing velocity corresponds to negative acceleration. Therefore, the correct interpretation is that the acceleration is negative during this time interval.

• Acceleration is negative → Correct, as the graph is concave downward indicating decreasing velocity.
• Velocity is increasing → Incorrect, since the slope is decreasing.
• Displacement is negative → Incorrect, because the sign of displacement cannot be inferred from the shape alone.
• Motion is uniform → Incorrect, as a curved graph implies non-uniform motion.