Question

The distance between planets varies as they move in their orbits. The minimum distance from the Earth to Mars is about 0.35 AU. About how many kilometers is that?
15,000,000 km
25,000,000 km
55,000,000 km
70,000,000 km

Answer 1

C- 55,000,000 km
Earth to Mars is 54.6 million km, but rounded up equals 55 million.

Answer 2

The distance between the earth and mars is given as 0.35 AU.

AU stands for astronomical unit. It is the macroscopic unit of distance which is used for distance measurement between celestial bodies.

One astronomical unit is defined as the mean distance between the sun and earth.The distance between earth and sun is approximately 150 million kilometre. Hence -

                                      $1 AU=150 *10^6 km$

As per the question we have to convert the mean distance between earth and mars from AU unit to kilometre.

The mean distance is given as  0.35 AU

                                                $= 0.35*150 *10^6 km$

                                                 $=52.5*10^6 km$

                                                 $= 52,500,00 km$

The calculated value is approximately close to 55,000,00 km.

Hence option C is right.