Distance-time graph for stop and speed change

Steps:

• Cyclist travels to shop at constant speed v: straight line with slope v.
• Stops for 5 minutes: horizontal line segment.
• Returns downhill at 2v: steeper straight line with slope 2v.
• Total distance increases throughout, with flat pause and final steeper rise.

Why D is correct:

• Matches constant speeds with 5-min flat section, per s = vt for uniform motion.

Why the others are wrong:

• A: No flat section, ignores stop.
• B: Curved lines suggest acceleration, not constant speeds.
• C: Decreasing distance implies backward motion, not total distance traveled.

Final answer: D