Laboratory work: studying the motion of a body thrown at an angle
The aim is to test how the range of a ball depends on the launch angle. Equipment: a ballistic launcher (spring gun) clamped to the table edge, a metal ball, a measuring tape, white and carbon (copy) paper. We set the launcher first at 30°, then at 45° (the angle is measured with a protractor), fire the ball and find the landing point from the mark on the paper; at each angle the experiment is repeated at least 3 times. For each angle the mean range lmean = (l₁ + l₂ + l₃)/3 and absolute errors Δlᵢ = |lᵢ – lmean| are found; the mean of these gives the error of the result: l = lmean ± Δlmean. By theory s = υ₀²sin2α/g, so the range is greatest at 45°, and at 30° it should be about sin60° ≈ 0.87 of the range at 45°. We compare the result with theory and explain the difference (air resistance, size of the ball, launch height). Safety: the device is used only under the teacher’s supervision, nobody stands in the line of fire, and the ball must never be aimed at a person.
In class: draw your table (angle; 3 ranges; mean; error). Practise with the sample numbers your teacher gives, then enter real measurements. Only the teacher operates the launcher.