Dr Strange is an impenitent pragmatist who does not believe in out-of-body experiences. A nun wants to correct his mistake by hitting him in the chest with a constant force and knocking the astral body (with mass identical to that of Dr Strange, m = 80 kg) out of him. If the impact (contact of the fist and the chest) took t = 0.1 s and the astral body was moving with velocity v = 5 m·s⁻¹ afterwards, what force did the nun hit with? The body of Dr Strange itself does not move, violation of mass conservation is not our problem. Mirek was relaxing and watching trailers.