Question

A light year is the distance that light can travel in one year. 1 light year = 9,460,000,000,000 km.

1. Express one light year in scientific notation.
2. The average distance between Earth and Sun is 1.496 × 108 km. Is the distance between Earth and the Sun greater than, less than or equal to one light year?

Answer 1

a. Given, 1 light year = 9,460,000,000,000 km

For standard form = 946 × 10¹⁰ km

= `946/100 xx 10^10 xx 100` km

= 9.46 × 10¹² km

b. The average distance between Earth and Sun = 1.496 × 10⁸ km

∴ Distance between Earth and Sun = `1.496/10000 xx 10^8 xx 10^4` km

= 0.0001496 × 10¹² km

Since, 9.46 > 0.0001496

So, the distance between Earth and Sun is less than one light year.