A lightyear is the distance light travels in a year. Light travels 186,000 miles in a second. How many trillion miles long is a lightyear?

Question

A lightyear is the distance light travels in a year. Light travels 186,000 miles in a second. How many trillion miles long is a lightyear?(Round your answer to two decimal places.) 

Answer 1

1 sec, 1.86 x 10⁵

1 hr, (1.86 x 10⁵) (3.6 x 10³), 6.696 x 10⁸

1 day, (6.696 x 10⁸ ) (2.4 x 10), 16.0704 x 10⁹, 1.60704 x 10¹⁰

1 yr, (1.60704 x 10¹⁰) (3.65 x 10²), 5.865696 x 10¹²

 

 

Answer 2

There are 365.25 days in a year.

There are 24 hours in a day.

There are 60 minutes in an hour.

There are 60 seconds in a minute.

 

Therefore there are 365.25 * 24 * 60 * 60 = 31557600 seconds in a year.

 

Since light travels 186,000 miles per second, light travels 186000 * 31557600 = 5869713600000 miles in a lightyear.

 

Rounded to two decimal places and in trillions of miles, this is 5.87 trillion miles.