Mach refers to the speed of what?

More Questions:

Which sign of the zodiac is represented as a man pouring water from a jar?

What is a turkey stuffed with a duck stuffed with a chicken called?

What is the Jewish New Year called?

Carl Lewis won gold medals in what event at four consecutive Summer Olympics?

What primary alcohols go into the standard Grasshopper cocktail?

How many dot positions are there in each letter of the Braille alphabet?

From 1997-2002, what computer company used the ad slogan "Think different"?

What pieces of fruit contain three princesses in Sergei Prokofiev's most famous opera?

In what city would you find Grant Park?

Who starred in the lead male role in the 1968 movie "Planet of the Apes"?

What year was the TV show "SpongeBob SquarePants" first aired in?

In the TV show "The Simpsons', what was the name of Comic Book Guy's dead dog?

Which actor/stand-up comedian was prominently featured in the 2009 documentary "Good Hair"?

John Carpenter's "Assault on Precinct 13" is an homage to what classic Howard Hawks western?

In what country was Albert Einstein born?