AY 101-0051                                                        Summer 2011
                                   QUIZ #2

1. Newton found that the gravitational force between two objects
   a) depends only on their masses. 
   B) DEPENDS ON THEIR MASSES AND SEPARATION.
   c) depends on their chemical composition.
   d) changes with time.

2. The Earth has 80 times the mass of the Moon. If the gravitational force with which the Earth pulls the Moon is equal to 1, the force with which the Moon pulls the Earth is
   a) 80                              B) 1    			c) 1/80	d) zero.


3. According to Newton's laws of motion, if something moves at constant velocity,
   a) a constant force is propelling it.
   b) it must be freely falling in a gravitational field.
   C) NO (UNBALANCED) FORCE IS ACTING ON THE OBJECT.
   d) its acceleration must be at right angles to its motion.

4. Which of these does not involve acceleration?
   a) bringing a car to  a stop.            		 
   b) turning a vehicle around a corner.	
   C) A CHAIR BEING PUSHED ACROSS THE FLOOR IN A STRAIGHT LINE AT CONSTANT SPEED.
   d) a bucket being whirled around in a circle, held in place by a rope. 

5.  An object in orbit 22,300 miles above the Earth’s equator is in geosynchronous orbit, appearing to hang motionless over the rotating Earth. If the Earth rotated twice as fast, this orbital location would be
   A) CLOSER.                       	c) at the same distance.
   c) farther away.          		d) nonexistent.

6. The underlying cause of tides is
   a) water under the Moon being more strongly attracted to it.
   b) the different strength of gravity acting on solids and liquids.
   C) THE WAY THE STRENGTH OF GRAVITY FALLS OFF WITH DISTANCE. 
   d) the Earth's rotation imparting a centrifugal acceleration to water.

7. The compositions of objects in different zones of the solar system largely reflect
   a) differences in the makeup of the material surrounding the forming Sun.
   b) the Sun’s gravity.
   C) THE TEMPERATURES IN THE EARLY SOLAR SYSTEM.
   d) chemical changes over the history of the Solar System.

8. The planets closest to the Sun have the largest proportion of
   A) METALLIC ELEMENTS.    		c) ices.
   b) rocky material.                 	d) hydrogen and helium.

9. The chemical building blocks of the solar system are broadly classified as
   a) earth, air, fire, and water.
   b) hydrogen, helium, lithium, beryllium.
   C) HYDROGEN/HELIUM, ICES, ROCK, AND METALS.
   d) terrestrial, Jovian, and cometary.

10. Most minor planets (or asteroids) are located
   a) beyond the orbit of Neptune.
   B) BETWEEN THE ORBITS OF MARS AND JUPITER.
   c) between the orbits of Earth and Mars.
   d) in orbits with simple ratios to Jupiter's (such as ½ or 2/3 its period).