Distance from area under speed-time graph

Steps:

• The graph forms a right triangle with base 10 s and height 5 m/s, indicating constant acceleration from rest.
• Base represents total time: 10 s.
• Height represents maximum speed reached: 5 m/s.
• Calculate area: (1/2) × base × height = (1/2) × 10 × 5 = 25 m.

Why B is correct:

• Distance traveled equals the area under the speed-time graph, per the definition of displacement as the integral of velocity over time, yielding exactly 25 m.

Why the others are wrong:

• A: Assumes zero acceleration (area too small at 20 m).
• C: Assumes constant speed of 3 m/s (rectangular area of 30 m, ignoring acceleration).
• D: Assumes constant speed of 4 m/s (overestimates rectangular area at 40 m).

Final answer: B