AS Daily A Level Physics question
Two identical balls are launched from the same level at the same angle to the horizontal. Ball B is launched at 1.5 times the launch speed of Ball A. Air resistance is negligible. Which statement must be true?
Answer
The correct answer is C.
Correct: C — Ball B’s time of flight is 1.5 times Ball A’s. The vertical component of speed scales with the launch speed at fixed angle, so the up–down time scales linearly: multiplying speed by 1.5 multiplies time by 1.5. A The horizontal range at fixed angle scales with the square of launch speed, so it would be 1.5^2 = 2.25 times, not 1.5 times. B Maximum height also depends on the square of the vertical component, so it would be 2.25 times, not 1.5 times. C Time of flight depends linearly on the vertical component, so a 1.5× increase in launch speed gives a 1.5× increase in time. D With no air resistance the horizontal speed is constant and scales linearly with launch speed, so it would be 1.5 times, not 2.25 times.