# Semi-holonomic constraints (analytical mechanics)

1. May 9, 2008

### maria clara

m equations of semi-holonomic constraints can be put in the form:

fi=(q1,q2,....,qn,$$\dot{q}$$1,...,$$\dot{qn}$$)

but "commonly appears in the restricted form:

$$\Sigma$$aikdqk +aitdt = 0

(i,k,t preceded by "a" should appear in subscript and the sum is over k)

I don't understand this form. what are the coefficients aik and ait? can they be functions of q or q dot?
I don't understand how is it possible for these two equations to be equivalent.
consider for example the following equation of a non-holonomic constraint: q1^2+q2dot=0
what would the second form of this equation look like?

Last edited: May 9, 2008
2. May 9, 2008

### maria clara

sorry for the last post (couldn't delete it for some reason)... I was confused, but now I realize the second equation is not exactly equivalent to the first, but represents only a special case which is quite common.

3. May 9, 2008

### siddharth

I don't think you can delete the first post in a new thread.

Also, have you taken a look at the Latex tutorial? It's an easy way to display equations.

4. May 9, 2008

### maria clara

now I have, thanks