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AS Daily A Level Physics question

2026-01-19 OCR A Projectile motion (M3.1.3) 3.1.3(b)

In a school lab, a student uses a launcher to fire a rubber ball from ground level at a fixed angle to the horizontal. Air resistance is negligible. They double the launch speed while keeping the angle the same. Which outcome must occur?

  1. A The maximum height becomes twice as large.
  2. B The horizontal range becomes four times larger. (correct)
  3. C The time the ball is in the air becomes four times longer.
  4. D The initial vertical component of speed stays the same.

Answer

The correct answer is B.

Correct: B — The horizontal range becomes four times larger. A The maximum height depends on the square of the vertical launch speed, so doubling the launch speed makes the maximum height four times larger, not twice. B Range on level ground at fixed angle depends on the square of the launch speed, so doubling the speed makes the range 4× (with air resistance neglected). C The time of flight scales with the vertical component of speed, so it doubles, not quadruples. D At a fixed angle, doubling the overall speed doubles both horizontal and vertical components, so the vertical component does not stay the same.