Grade 12 · Theory
Equations for projectiles
Vertical projectile motion · about 3 min
The same three equations of motion apply, with a replaced by g.
Key points- vf = vi + gΔt
- Δy = viΔt + ½gΔt²
- vf² = vi² + 2gΔy
- Δy is displacement, which can be negative if the object ends below its start.
- Displacement (Δy) — change in vertical position.
EXAM TIP
an object returning to its launch height has Δy = 0 — substituting that solves for total flight time immediately.