{
  "correct_letter": "B",
  "correct_formula": "v = v_0 + g·t",
  "annotation": "Environment: g=9.81, F_drag=!=0\nGround: e=0.5\nBaseball: d = 0.07, e = 0.55, h = 0.93, v_0 = 0.0\nSteelBall: d = 0.04, e = 0.6, h = 1.4, v_0 = 0.0",
  "choices": [
    "Q = m·c·ΔT",
    "v = v_0 + g·t",
    "v = v_0·cos(g·t / v_0)",
    "v_final = -e·v_impact"
  ],
  "correct_index": 1,
  "physics_type": "FreeFall",
  "seed": "FreeFall|Gravity/Freefall/13",
  "is_realworld": true,
  "dropped_wrong_formulas": [
    "P + (1/2)·ρ·v² + ρ·g·h = constant"
  ]
}