Universal Gravitation                                   Name:

1. The evidence that stimulated Newton to propose the law of universal gravitation emerged from a

study of ____.

a. the motion of the moon and other celestial or heavenly bodies

b. the fall of an apple to the Earth

c. the gravitational interaction of smaller objects upon the Earth

d. ...nonsense! There was no evidence; it was just proposed as a theory.

2. The universal of Newton's law of universal gravitation is a common source of confusion. The

universal means that _____.

a. the amount of gravitational forces is the same for all objects.

b. the acceleration caused by gravity is the same for all objects.

c. the force of gravity acts between all objects - not just between the Earth and an object, but also

between two people. All objects with mass attract.

3. According to Newton's gravitation law, the force of gravitational attraction between a planet and an

object located upon the planet's surface depends upon _____. Choose all that apply.

a. the radius of the planet b. the mass of the planet

c. the mass of the object d. the volume of the object

e. … nonsense! None of these variables affect the force of gravity.

4. The more massive that an object is, the ______ (more, less) that the object will be attracted to Earth.

5. The more massive the Earth is, the ______ (more, less) that another object will be attracted to Earth.

6. The greater that Earth's radius is, the ______ (more, less) that another object will be attracted to

Earth.

7. In the mathematical form of Newton's law of universal

gravitation (see equation at right), the symbol G

stands for _____.

a.     gravity b. the acceleration of gravity c. the gravitational constant

8. TRUE or FALSE:

The value of G (in the equation above) is an enormously large number; that explains

why (at least in part) the force of gravitational attraction between the Sun and the very

distant Earth is such a large number.

9. TRUE or FALSE:

Two lab partners attract each other with a gravitational force. However,

it is impossible to calculate such a force since it is only an unproven

theory.

10. TRUE or FALSE:

The notion that any two objects attract each other gravitationally is a

theory. There is no empirical evidence for such a notion.

11. Orbiting astronauts on the space shuttle do not have weight in space because _____.

a. there is no gravity in space b. there is no air resistance in space

c. there are no scales in space d. the food is terrible and they work all the time

e. ... nonsense! The astronauts do have weight in space.