I have played the piano since I was 3. Its an acoustic stringed instrument where the strings are hit by hammers.
Oh wow, I would love to play the piano, what are some of the top brands ?
Possibly the most famous is Steinway & Sons. Also the term piano is a shortened form of the italian word "pianoforte" which actually means "soft" and "loud" respectively.
When was the piano invented ? and by whom?
It was invented around the year 1700 by Bartolomeo Cristofori.
How long do people have to study to become semi-proficient with the piano ?
It took me almost 10 years to get good. I guess it depends on the person. 
Have you ever had a public performance ?
the stronger the attack. The name was created as a contrast to harpsichord, a musical instrument that does not allow variation in volume. The first fortepianos in the 1700s had a quieter sound and smaller dynamic range.
An acoustic piano usually has a protective wooden case surrounding the soundboard and metal strings, which are strung under great tension on a heavy metal frame. Pressing one or more keys on the piano's keyboard causes a padded hammer (typically padded with firm felt) to strike the strings. The hammer rebounds from
Piano
The piano is an acoustic, stringed musical instrument invented in Italy by Bartolomeo Cristofori around the year 1700 (the exact year is uncertain), in which the strings are struck by hammers. It is played using a keyboard, which is a row of keys (small levers) that the performer presses down or strikes with the fingers and thumbs of both hands to cause the hammers to strike the strings. 
The word piano is a shortened form of "pianoforte", the Italian term for the early 1700s versions