If the lorentz factor γ dt/dτ = e/mc 2 is √5 ≅ 2.236, what is the proper velocity w dx/dτ in units of c?
CREATE TABLE "table1_15314901_1" (
  "condition_parameter" text,
  "coordinate_velocity_v_dx_dt_in_units_of_c" text,
  "velocity_angle_in_i_radians" text,
  "proper_velocity_w_dx_d_in_units_of_c" text,
  "lorentz_factor_dt_d_e_mc_2" text
);
SELECT "proper_velocity_w_dx_d_in_units_of_c" FROM "table1_15314901_1" WHERE "lorentz_factor_dt_d_e_mc_2"='√5 ≅ 2.236';