What is the magnitude of the force of gravity between two 1 000 kg cars which are separated by a distance of 25.0 kilometers on an interstate highway? The force between these two cars will be (Hints--you need all distances to be in meters and all masses to be in kg; use Newton's Law of universal Gravitation. You may assume that the cars' masses are both known to the nearest kilogram, so your answer should have 3 significant figures.)