At a particular instant, two asteroids in inter-stellar space are a distance

Question

r = 20 km apart. Asteroid 2 has 10 times the mass of asteroid 1, m2 = 10 m1.

1. If the acceleration of the asteroid 1 toward the asteroid 2 is 1.0 m/s2
, what is
the acceleration of the asteroid 2?

Answer 1

F = m a
F is the same on both (Third Law)

m2 a2 = m1 a1
10 m1 a2 = m 1 a1

a 2 = a1 /10
if a1 is 1
then a2 = 0.1 m/s^2