The guideline for seating distance from a widescreen tv is generally 1.5 to 2 times the width of the screen. For all tvs, the height of the tv should be set such that the center of the screen is at eye level when you are seated. Naturally, personal preferences override any of that and you can experiment to find out what suits you best.
Using said guidelines, you could sit anywhere from 75 to 100 inches away from a 50" LCD - So 9.5 ft away should be fine as its actually a bit further away than the general rules would specify.