# What are cyclic coordinates?

## What are cyclic coordinates?

A cyclic coordinate is such a coordinate on which the momentum of the particle does not depend. You can further watch it in this link. Cyclic Coordinate: If the expression for Lagrangian doesn’t involve a coordinate explicitly,then this coordinate is called cyclic coordinate or ignorable coordinate.

## What are cyclic coordinates in Lagrangian?

A generalized coordinate that does not explicitly enter the Lagrangian is called a cyclic coordinate and the corresponding conserved quantity is called a constant of motion.

What is the significance of cyclic coordinate?

If a generalized coordinate qj doesn’t explicitly occur in the Hamiltonian, then pj is a constant of motion (meaning, a constant, independent of time for a true dynamical motion). qj then becomes a linear function of time. Such a coordinate qj is called a cyclic coordinate.

### What are ignorable coordinates?

a generalized coordinate of a mechanical system that does not appear in the system’s Lagrangian function or other characteristic functions. The presence of ignorable coordinates simplifies the integration of the corresponding differential equations of motion of a mechanical system.

### What is conserved in a Lagrangian?

In other words, if the Lagrangian is independent of coordinate q i q_i qi, then the quantity ∂ L / ∂ q i ˙ \partial \mathcal{L} / \partial \dot{q_i} ∂L/∂qi˙ is conserved! (Some jargon: we say the coordinate q i q_i qi which the Lagrangian doesn’t depend on is a cyclic coordinate.)

What is conserved in Lagrangian equation?

So Lagrange’s equation tells us that the total linear momentum is conserved!

## What do you mean by generalized coordinates?

In analytical mechanics, generalized coordinates are a set of parameters used to represent the state of a system in a configuration space. These parameters must uniquely define the configuration of the system relative to a reference state.

## What is meant by canonical transformation?

From Wikipedia, the free encyclopedia. In Hamiltonian mechanics, a canonical transformation is a change of canonical coordinates (q, p, t) → (Q, P, t) that preserves the form of Hamilton’s equations.

What is statement of Hamilton’s principle?

. Hamilton’s principle says that for the actual motion of the particle, J = 0 to first order in the variations q and qq . That is, the actual motion of the particle is such that small variations do not change the action.

### What is the definition of cyclic coordinate?

If a generalized coordinate q j doesn’t explicitly occur in the Hamiltonian, then p j is a constant of motion (meaning, a constant, independent of time for a true dynamical motion). q j then becomes a linear function of time. Such a coordinate q j is called a cyclic coordinate. The above quote is taken from p. 4 in Ref. 1.

### What is a cyclic coordinate in the Hamiltonian?

If a generalized coordinate q j doesn’t explicitly occur in the Hamiltonian, then p j is a constant of motion (meaning, a constant, independent of time for a true dynamical motion). q j then becomes a linear function of time. Such a coordinate q j is called a cyclic coordinate.

Is Q J A cyclic coordinate?

Such a coordinate q j is called a cyclic coordinate. The above quote is taken from p. 4 in Ref. 1. What I don’t understand is why q j is a linear function of time if p j is constant in time.

## How do you find the linear function of a cyclic coordinate?

A cyclic coordinate $q_j$ does nothave to be an linear function of $t$. Example:Consider two canonical pairs $(q,p)$ and $(Q,P)$ with Hamiltonian $H= p Q +P$. Then $q$ is cyclic, and therefore $p$ is a constant of motion. $dot{Q} =frac{partial H}{partial P}=1$, so $Q$ is a linear function of time.