{
  "correct_letter": "B",
  "correct_formula": "m_1·v_1i + m_2·v_2i = (m_1+m_2)·v_f",
  "annotation": "Environment: g=-9.81, F_drag=0.0\nGround: mu_s=0.0, mu_k=0.0\nLeftPlayDohCube: a = 2.0, e = 0.0, m = 10000.0, v_0 = 5.5\nRightPlayDohCube: a = 3.0, e = 0.0, m = 33750.0, v_0 = 1.1",
  "choices": [
    "W_friction = μ_k·(m_1 + m_2)·g·d",
    "m_1·v_1i + m_2·v_2i = (m_1+m_2)·v_f",
    "E_k_f = (m_1²·v_1i² + m_2²·v_2i²) / (2·(m_1 + m_2))",
    "ΔS = Q_rev / T"
  ],
  "correct_index": 1,
  "physics_type": "PerfectlyInelasticCollision",
  "seed": "PerfectlyInelasticCollision|benchmark/perfectly_inelastic_collision/7"
}