Of course, in the special (&idealized) case of CONTACT forces, the joining line segment is of zero length, and hence, the conservation of total angular momentum is preserved anyhow we look at it...Shooting star said:I don't have the book right now with me, so I'm a bit unsure of exactly what you don't like. I presume that you are talking about system of particles. The third law states that the action and reaction forces are equal and opposite, but does not say that they lie along the line joining the particles. Only in the latter case will the total angular momentum of a system be conserved if the external torque is zero.
That's a typical case, yes.Shooting star said:So, the case you are talking about is more pertinent for collisions, it seems to me?
The conservation of angular momentum is a fundamental principle in physics that states that the total angular momentum of a system remains constant unless acted upon by an external torque. It is a consequence of Newton's third law of motion, which states that for every action, there is an equal and opposite reaction.
Newton's third law states that when two objects interact, they exert equal and opposite forces on each other. In the case of angular momentum, this means that for every torque exerted on an object, there is an equal and opposite torque exerted by the object on its surroundings. This leads to the conservation of angular momentum because the total torque on the system is always zero, and thus, the total angular momentum remains constant.
No, according to the conservation of angular momentum, the total angular momentum of a system cannot be created or destroyed. It can only be transferred from one object to another within the system.
The conservation of angular momentum applies to everyday objects in the same way it does to more complex systems. For example, when you spin a top, the angular momentum remains constant unless acted upon by an external torque, such as friction from the surface. Similarly, when an ice skater pulls their arms in, their angular momentum decreases, but the total angular momentum of the system remains constant.
The conservation of angular momentum has many practical applications, such as in the design of satellites and spacecraft, where precise control of angular momentum is crucial for stability. It is also essential in understanding the motion of celestial bodies, such as planets and stars. In everyday life, the conservation of angular momentum is used in various sports, such as ice skating and gymnastics, where athletes use their body's angular momentum to perform impressive moves and routines.