Velocity-time graphs
3 marks · NormalA ball is rolled down a slope. The velocity–time graph for the ball shows a straight line with a positive gradient. Explain what this tells you about the ball’s acceleration and movement, using ideas from Galileo’s experiments.
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The ball is accelerating at a constant rate (uniform acceleration), just as Galileo observed in his experiments with balls on slopes.
Must show: links straight line to uniform acceleration, mentions increasing speed, references Galileo
Common mistakes: calling the motion constant velocity instead of acceleration
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Marking points
B1 · 1 mark · Explains the positive straight line means constant (uniform) acceleration.
B2 · 1 mark · Describes that the ball is speeding up.
B3 · 1 mark · Refers to Galileo’s experiment/ideas.
Worked solution
A straight line with a positive gradient means the ball’s speed is increasing at a steady rate, showing constant acceleration. This matches what Galileo discovered: for a ball rolling down a slope, velocity increases uniformly with time.