Question

Scientists use a unit of measure known as an astronomical unit, or AU, to describe distances within the solar system. The AU is defined to be 149,597,870.700 kilometers, which is the mean distance from Earth to the Sun. The mean distance from the planet Jupiter to the Sun is 5.2 AU. What is this distance in kilometers, expressed in scientific notation?

A.
2.9
×
10
7
kilometers

B.
7.8
×
10
7
kilometers

C.
6.7
×
10
8
kilometers

D.
7.8
×
10
8
kilometer

Answer 1

1 AU = 1.495978707×10^8 km. Multiply by 5.2:

5.2 × 1.495978707×10^8 = 7.7790892764×10^8 km ≈ 7.8×10^8 km.

Answer: D.