Q: How high in the sky can those lights at the 9/11 Memorial be seen? More than 100,000 feet? Higher?

— Patrick Kelly, Covington

A: It's unknown how high the twin beams that make up the Tribute in Light can be seen, a National September 11 Memorial & Museum spokesman told Q&A on the News in an email, but it's been reported that they are visible from as far as 60 miles away. Each beam is made up of 44 custom-designed, high-intensity searchlights that are arranged in two 48-foot squares near the World Trade Center site, according to 911memorial.org, the official website. The lights are turned on at sunset on Sept. 11 and turned off at dawn on Sept. 12 every year to mark the anniversary of Sept. 11, 2001.

Q: I recently read a story about Apple’s iPhone in China and saw a currency I wasn’t familiar with called the renminbi. Can you tell me more about it?

— Richard Clarke, Atlanta

A: Renminbi, which means "the people's currency," is the official name of China's currency. It was introduced to communist China in 1949 and is often referred to as the yuan, which actually is a denomination in the renminbi system, according to a BBC News article. A comparable example is the British pound being a unit of the pound sterling, the name of British currency. Yuan means dollar in Chinese, but the word "kuai," which is slang for yuan, like "buck" is for dollar in the U.S., often is used, the article states.