QCE Physics — Unit 3
Projectile Motion — Flashcards & Quiz
Projectile motion combines two independent one-dimensional motions: constant horizontal velocity and constant vertical acceleration (g = 9.8 m s⁻² downward). QCE Physics Unit 3 treats projectiles as a go-to calculation and derivation topic, and you are expected to resolve the launch velocity into components, apply kinematic equations separately, and solve for range, maximum height or time of flight.
Sample Flashcards
Q1: Describe the two independent components of projectile motion.
Horizontal: constant velocity (a = 0), x = v_x t. Vertical: constant acceleration g = 9.8 m s⁻² downward. Components are independent — horizontal does not affect vertical.
Q2: Find range and max height for a projectile at angle θ.
v_x = v cos θ, v_y = v sin θ. H = v_y²/(2g). T = 2v_y/g. R = v² sin 2θ / g. Max range at 45°.
Q3: How do you find velocity at any point during flight?
v = √(v_x² + v_y²), v_y = v_y₀ − gt. Direction: tan θ = |v_y|/v_x below horizontal.
Q4: How does air resistance affect projectiles?
Drag reduces horizontal speed, max height and range. Trajectory becomes asymmetric — steeper descent than ascent.
Sample Quiz Questions
Q1: Horizontal velocity stays constant without air resistance.
Answer: TRUE
No horizontal force → no horizontal acceleration.
Q2: Launch angles 30° and 60° give the same range at equal speed.
Answer: TRUE
Complementary angles: sin 2(30°) = sin 2(60°).
Q3: At the peak, both velocity and acceleration are zero.
Answer: FALSE
Vertical velocity = 0 but horizontal velocity persists and g acts throughout.
Last updated: March 2026 · 4 flashcards · 3 quiz questions