Mathematics for IGCSE & O level - Graphs In Practical Situations (Section 5 - No. 7)
When is the speed of an object constant on a distance-time graph?
When the line is curved.
When the line is horizontal.
When the line is a straight, non-horizontal line.
When the line is decreasing.
Paliwanag
Constant speed is represented by a straight line on a distance-time graph. A horizontal line is stationary (zero speed).