Answer:
On Earth all bodies have a weight, or downward force of gravity, proportional to their mass, which Earth's mass exerts on them. Gravity is measured by the acceleration that it gives to freely falling objects. At Earth's surface the acceleration of gravity is about 9.8 metres (32 feet) per second per second.
A. 1/9
Explanation:
The gravitational force between two objects is given by

where
G is the gravitational constant
m1 and m2 are the two masses
r is the distance between the two masses
From the formula, we see that the magnitude of the force is inversely proportional to the square of the distance: therefore, if the distance is tripled (increased by a factor 3), the magnitude of the force changes by a factor

In the frame of reference of anybody in the car.
When they meet the 40-kg boy would have moved a distance of 6 m.
<h3>Distance moved by the 40 kg boy</h3>
Apply the principle of center mass;
Take the 40 kg mass as the reference point;
X(40 kg) = (40kg x 0 + 60kg x 10 m)/(40 kg + 60 kg)
X(40 kg) = (600)/(100)
X(40 kg) = 6 m
Thus, when they meet the 40-kg boy would have moved a distance of 6 m.
Learn more about distance here: brainly.com/question/2854969
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