2025 HSC Physics Q28: Projectile launch at angle
Q28 (4 marks): A rider launches from a ramp at angle θ = 20° and must land on a second ramp. Calculate the minimum speed required to clear the gap between the ramps (given distance and height dat.
What went wrong:
Students resolved velocity into components but applied kinematic equations incorrectly. The horizontal and vertical components must be treated separately using separate kinematic equations. Many students tried to apply one equation to both components or forgot to resolve velocity at all.
What they needed to do: Resolve initial velocity: vx = u cos20°, vy = u sin20°. Vertical: use s = vyt + ½at2 with vertical displacement from the question to find t. Horizontal: s = vx × t gives the horizontal distance. Substitute values and solve for u. Answer: u ≈ 15.6 m/s.
Posted Jul 20, 2026, 10:30 PM UTC