How to deparent object between frames in Maya? I'm a computer-science student making a video with motion-capture data in Maya for a course. I am a real beginner.

In our story we have a character that loses her sword at a certain point. Our sword is parented to her hand and we have motion capture data (of the character) losing it. How do we deparent the sword in the middle of that animation to animate it separately? (Or, preferably, apply a basic-physics system to it so it falls realistically?)
Use constraints to do this:


Select the parent (the hand), then shift + select the child (the sword). Warning, selection order matters.
Rigging > Constraint > Parent Constraint > activate Maintain Offset if there's an offset between both pivot points.
Set a translation keyframe (shit + w) and a rotation keyframe (shift + e) on the sword.
By setting those keyframes, the sword now has a new attribute in the Channel Box, called Blend Parent 1. You can animate it to choose between unconstrained (value = 0) or constrained (value = 1) by the hand. If unconstrained, you have to set keyframes on the sword to place it inside the worldspace.