What does the "c" in the equation e=mc^2 stand for?

More Questions:

Which country were the 1992 Winter Olympic Games held in?

What wine barrel size contains 10 gallons?

In Greek mythology, who was Paris" wife before he was smitten by Helen?

What instrument did Teddy Wilson play in the Benny Goodman Swing Quartet?

Minsk is the capital of which European country?

Moosehead Lake is the largest lake in which US state?

What is a theodolite used for?

In The Simpsons, who sings to Homer and the other astronauts in space?

Who was the main actor in the movie "A Beautiful Mind"?

What was Bette Midler’s only #1 song on the Billboard Hot 100 singles chart?

What 1993 film's title character has the first name Euphegenia?

Who directed the movie "Blade Runner"?

Who rode his horse Copenhagen at the Battle of Waterloo?

Which US vice president shot a Texas attorney while out hunting quail in 2006?

What was a Portuguese moidore?