{
  "correct_letter": "B",
  "correct_formula": "e = (v_2f - v_1f) / (v_1i - v_2i)",
  "annotation": "Environment: g=-9.81, F_drag=0.0\nGround: mu_s=0.0, mu_k=0.0\nWalnutCube1: a = 2.0, e = 0.5, m = 5120.0, v_0 = 2.0\nOakCube: a = 2.0, e = 0.5, m = 6000.0, v_0 = 1.0\nCherryCube: a = 2.0, e = 0.5, m = 5040.0, v_0 = 0.0",
  "choices": [
    "σ = F/a² = E·ε",
    "e = (v_2f - v_1f) / (v_1i - v_2i)",
    "J = m_1·m_2·(v_1i - v_2i)·(1+e) / (m_1 + m_2) · sinθ",
    "v = f·λ"
  ],
  "correct_index": 1,
  "physics_type": "InelasticCollision",
  "seed": "InelasticCollision|benchmark/inelastic_collision/9"
}