When earth pulls on an object, that object also pulls on earth. the values of these two forces are . this phenomenon can be explained using newton’s law. we see the object move but not earth because there’s a difference in their .

The values of these two forces are equal. Your weight on Earth is equal to the Earth's weight on you. When you and the Earth fall toward each other, your acceleration is greater than the Earth's acceleration, because your mass is less than the Earth's mass.

  concave means having an outline or surface that curves inward like the interior of a circle or sphere. so the mirror curves inward.