The law of non weightlessness, also known as Newton's first law of motion, states that an object at rest will remain at rest and an object in motion will continue in motion with the same velocity unless acted upon by an external force.
In space, there is no gravitational force to act upon objects, so they will continue to move in a straight line at a constant speed unless acted upon by another force. This is why astronauts in space experience a feeling of weightlessness.
The law of non weightlessness is part of Newton's three laws of motion. The second law states that the acceleration of an object is directly proportional to the net force acting on it and inversely proportional to its mass. The third law states that for every action, there is an equal and opposite reaction.
The law of non weightlessness is crucial in designing spacecraft because it allows engineers to understand how objects will behave in a weightless environment. This knowledge is essential in creating systems and mechanisms that will function properly in space.
The law of non weightlessness applies to objects that are not acted upon by external forces. However, in the presence of external forces such as air resistance or friction, the motion of an object may be affected, and the law may not hold true. This is why spacecraft need to be designed to withstand these external forces in order to maintain their intended trajectory.