Spinnor said:
The mass of an object affects its motion by determining how much force is needed to accelerate it. Objects with greater mass require more force to accelerate compared to objects with less mass. Additionally, the greater the mass of an object, the greater its inertia, meaning it is harder to change its state of motion.
Motion with changing mass can occur in a variety of situations, such as when an object is accelerating, decelerating, or experiencing a change in direction. This can also occur when an object is gaining or losing mass, such as in a chemical reaction or when a rocket expels fuel.
The main difference between constant mass motion and motion with changing mass is that in constant mass motion, the mass of the object stays the same throughout the motion, while in motion with changing mass, the mass of the object changes. This can result in different equations and principles being applied to analyze the motion.
The acceleration of an object with changing mass can be calculated using Newton's second law of motion: F=ma. However, in this case, the force (F) must be calculated as the sum of all external forces acting on the object, including the change in mass. The mass (m) used in the equation should be the instantaneous mass at that point in time.
Conservation of momentum states that the total momentum of a system remains constant unless acted upon by an external force. In motion with changing mass, the mass of the system is changing, but as long as there are no external forces acting on the system, the total momentum will remain constant. This can be seen in situations such as a rocket launching, where the mass of the rocket is changing, but the total momentum of the rocket and its exhaust gases stays the same.
