1) Newton’s first law states that an object will remain at rest or in uniform motion (constant speed) in a straight line unless an external force acts on the body.In other words, when a body is at rest or moving at constant speed in a straight line (constant velocity), straight away you should know it is Newton’s first law. Next you must know these 3 basics concepts about 1st law:– forces acting on the body are balanced– net force / resultant force acting on the body is zero– there is no acceler