Phase space. Phase trajectories.

AI Thread Summary
Phase space is relevant for both kinematic and dynamic systems, as it can be applied to equations of motion in both contexts. In kinematics, the relationship between position and time can be expressed without time, leading to a trajectory equation. Similarly, in dynamics, phase trajectories can be derived by eliminating time from equations involving position and momentum. The discussion emphasizes that phase space is not limited to dynamic problems but is equally applicable to purely kinematic scenarios. Understanding phase space enhances the analysis of mechanical systems, regardless of their complexity.
LagrangeEuler
Messages
711
Reaction score
22
If I understand well like in kinematics where we could have eq of motion ##x=x(t)##, ##y=y(t)## and we get eq of trajectory with elimination of time. In dynamics we have ##x=x(t)##, ##p=p(t)## and with elimination of time we get eq of phase trajectory. Am I right?
 
Last edited:
Physics news on Phys.org
If I read your question correct, no. I see no reason why phase space can't be just as relevant for both for a purely kinematic set of equations as for a dynamical problem, even if we mostly use the term phase space in the later situation. For instance, phase space makes perfect sense also for simple mechanical systems which has only kinematic state (like position and velocity).
 
The rope is tied into the person (the load of 200 pounds) and the rope goes up from the person to a fixed pulley and back down to his hands. He hauls the rope to suspend himself in the air. What is the mechanical advantage of the system? The person will indeed only have to lift half of his body weight (roughly 100 pounds) because he now lessened the load by that same amount. This APPEARS to be a 2:1 because he can hold himself with half the force, but my question is: is that mechanical...
Some physics textbook writer told me that Newton's first law applies only on bodies that feel no interactions at all. He said that if a body is on rest or moves in constant velocity, there is no external force acting on it. But I have heard another form of the law that says the net force acting on a body must be zero. This means there is interactions involved after all. So which one is correct?
Thread 'Beam on an inclined plane'
Hello! I have a question regarding a beam on an inclined plane. I was considering a beam resting on two supports attached to an inclined plane. I was almost sure that the lower support must be more loaded. My imagination about this problem is shown in the picture below. Here is how I wrote the condition of equilibrium forces: $$ \begin{cases} F_{g\parallel}=F_{t1}+F_{t2}, \\ F_{g\perp}=F_{r1}+F_{r2} \end{cases}. $$ On the other hand...
Back
Top