vocab

6. the constant G in the equation for Newton's law of universal gravitation, it measures the strength of gravity.
7. a physical quantity varies inversely as another quantity squared
8. that which exists in the space surrounding a mass, electric charge, or magnet, so that another mass, electric charge, or magnet introduced to this region will experience a force.
9. the cutoff of light from the full moon when the earth is directly between the sun and the moon, so that the earth's shadow is cast on the moon.
11. a high or low tide that occurs when the sun, earth, and moon are all lined up so that the tides due to the sun and moon coincide, making the high tides higher than average and the low tides lower than average
12. a tide that occurs when the moon is halfway between a new moon and a full moon; the high tide is lower than average and the low tide is higher than average.

1. for any pair of objects, each object attracts the other object with a force that is directly proportional to the product of the masses of the objects, and inversely proportional to the square of the distance between their centers of mass.
2. the condition of free fall toward or around the earth, in which an object experiences no support force (and exerts no force on a scale).
3. a force field that exists in the space around every mass or group of masses.
4. the cutoff of light from the sun to an observer on the earth when the moon is directly between the sun and the earth.
5. a mass that has collapsed to so great a density that its enormous local gravitational field prevents light from escaping.
10. the deviation of an orbiting object from its path around a center of force caused by the action of an additional center of force