'न्यूटन का प्रथम नियम' (Newton's First Law) कहता है:

उत्तर: (C) Every object stays at rest or uniform motion unless acted upon by an external force — First Law (Law of Inertia): objects resist change in state. A book on table stays until pushed. A moving ball keeps moving until friction/air stops it. Inertia ∝ mass. Seatbelts protect against inerti...