英文字典中文字典Word104.com



中文字典辭典   英文字典 a   b   c   d   e   f   g   h   i   j   k   l   m   n   o   p   q   r   s   t   u   v   w   x   y   z   


安裝中文字典英文字典辭典工具!

安裝中文字典英文字典辭典工具!








  • Light-year - Wikipedia
    A light-year, alternatively spelled light year (ly or lyr [3]), is a unit of length used to express astronomical distances and is equal to exactly 9 460 730 472 580 8 km, which is approximately 9 46 trillion km or 5 88 trillion mi
  • What Is a Light Year? Definition and Examples - Science Notes and Projects
    The light year or light-year (ly) is a unit of length that is the distance light travels in a vacuum in one Earth year One light year is exactly 9460730472580 8 km (approximately 9 46 trillion kilometers or 9 46 x 10 12 km), which is approximately 5 88 trillion miles
  • What is a light-year? | Space
    A light-year is a measure of astronomical distance: Light travels through a vacuum at precisely 983,571,056 feet (299,792,458 meters) per second, making a light-year approximately 6 trillion
  • What Is a Light-Year? | NASA Space Place – NASA Science for Kids
    A light-year is the distance light travels in one Earth year Learn about how we use light-years to measure the distance of objects in space
  • What is a light-year? - Science@NASA
    Light-year is the distance light travels in one year Light zips through interstellar space at 186,000 miles (300,000 kilometers) per second and 5 88 trillion miles (9 46 trillion kilometers) per year
  • What is a light-year and how is it used?? - NASA
    A light-year is a unit of distance It is the distance that light can travel in one year Light moves at a velocity of about 300,000 kilometers (km) each second
  • What Is a Light-Year? Understanding Cosmic Distances
    A light-year is the distance light travels in a vacuum over the course of one year Multiply the speed of light by the number of seconds in a year, and you get the magic number: about 9 46 trillion kilometers, or roughly 5 88 trillion miles
  • What Is a Light-year? - HowStuffWorks
    To measure really long distances and how fast light travels, astronomers and other scientists use a unit called a light-year To reach the previously mentioned Proxima Centauri, it'd take 4 25 years at light speed


















中文字典-英文字典  2005-2009

|中文姓名英譯,姓名翻譯 |简体中文英文字典