Name ______________________		GSC 120  
 5/06/05  
 Fourth Exam

I.	True or False (1 point each). Indicate whether the statement is (A) True or (B) False.

1. 	Things float higher in saltwater than in freshwater.

2. 	The distance between adjacent nodes in a standing wave is one wavelength.

3. 	Waves travel faster in heavier strings.

4. 	A highly stretched rubber band vibrates faster than a less stretched one.

5. 	A composite volcano has a dome shape to it.

6. 	Buoyancy results from fluid pressure increasing with depth.

7. 	20-25% of Americans suffers from obesity.

8. 	A plunging breaker is a large air pocket followed by a smooth splash up. It forms when the bottom rises abruptly toward the shore.

9. 	A material, such as glass, that does not allow electricity to pass through is an example of an insulator.

II.	Multiple Choice (1 point each). Indicate which is the best response.

10.	Approximately what percentage of the earth's water is freshwater? 
	A.	3			B.	20
	C.	75			D.	97

11.	The majority of the stream flow in a permanent stream comes from  
	A. recent rainfall.			B. recent snow melt.
	C. groundwater. 			D. none of the above

12. 	Rainfall falling on Phoenix, Arizona will eventually empty into which ocean?  
	A. Atlantic			B. Gulf of Mexico
	C. Indian				D. Pacific

13. 	Groundwater is found in greatest quantities in soils with _____ porosity and _____ permeability.  
	A. high/high		B. high/low
	C. low/high		D. low/low

14.	A groundwater well should be dug to a depth  
	A. above the water table.
	B. at the top of the water table.
	C. above the zone of saturation.
	D. below the water table.

15.	Groundwater is most often treated to remove 
	A. bacteria.			B. toxic pollutants.
	C. dissolved minerals.	D. sediments.

16. 	Evaporation and ice formation lead to a(n) ______ in seawater salinity. 
	A. increase		B. decrease		C. no change

17.	Which of the following generally increases the density of water?  
	A. lower salinity
	B. lower temperature
	C. lower sediment levels

18.	How are frequency and period related?  
A. frequency and period are equal
B. frequency and period are reciprocals of each other
	C. frequency and period are unrelated
	D. additional information is needed

19.	What is a wave?  A wave is the propagation of
A. a pulse.			B. a disturbance.
	C. vibrating matter.	D. a medium.

20.	Sound waves may be characterized as  
	A. 	the propagation of alternate compressions and rarefactions.
	B. 	a longitudinal wave.
	C. 	molecules oscillating along the direction of the sound wave.
	D.  	all of the above.

21. 	How is the velocity of a wave related to its frequency and wavelength?  
A. v = fλ			B. v = f/λ
C. v = λ/f			D. v = f + λ 

22. 	Sound travels about 5,000 ft/s in seawater.  If a sonar device sent a sound straight down to the bottom of the sea and the returning echo was heard 0.50 s later, how deep was the ocean?  
A. 2500 ft	B. 5000 ft
	C. 1250 ft	D. 1000 ft

23.	Which types of waves transport energy?  
A. sound waves		B. light waves
	C. water waves		D. all waves transport energy

24.	What conditions are necessary to produce resonance in an object?  
A. 	The object must have at least one natural frequency of vibration.
	B. 	The object must be driven by an external vibrating force.
	C. 	The frequency of the external vibrating force must match the object's natural frequency of vibration.
	D. 	All of the above.

25.	Which of the following does not describe a standing wave?  
A. A resonant wave confined within two boundaries.
	B. A long wave that is stationary.
	C. A wave pattern of nodes and antinodes within boundaries.
	D. A reflected wave that interferes with an incoming wave.

26.	The fundamental frequency at which a string vibrates is  
A.	the frequency that determines the pitch.
	B. 	one of the frequencies that produce the sound quality characteristic of a particular musical instrument.
	C. 	the highest of the overtone frequencies.
	D. 	a frequency whose standing wave contains more than one antinode.

27. 	How are the overtones related to the fundamental frequency of a vibrating string?  Overtone frequencies
A. 	all have wavelengths longer than the fundamental.
	B. 	are integral multiples of the fundamental frequency.
	C. 	are fractions of the fundamental frequency.
	D. 	all vibrate with higher intensities than the fundamental frequency.

28. 	Cold water sinks below warm water because of ____________ differences.
	A. density 		B. pressure 
	C. color 			D. salinity
	E. <None of the above>

29. 	The Tacoma Narrows bridge is located in _______________.
	A. Washington D.C.		B. New York state
	C. San Francisco		D. Michigan
	E. <None of the above>

30. 	The speed of sound is
	A. 34 km/s		B. 340 m/s
	C. 3400 cm/s		D. 34000 mi/hr
	E. <None of the above>

31.	Humans can hear sound frequencies between:
A. 10 - 10,000 hertz		B. 20 - 20,000 hertz
C. 30 - 30,000 hertz		D. 25 - 15,000 hertz
E. <None of the above>

32. 	The amplitude of a sound wave is _____________.
A. how loud something is
B. the intensity of sound
C. displacement of wave from equilibrium
D. a complete vibration
E. <None of the above>

33. 	The lavas from Mount St. Helen's were _______________
A. basaltic			B. andesitic
C. rhyolitic			D. pyroclastic
E. <None of the above>

34. 	Shield volcanoes are associated with ______________ lava.
A. basaltic		B. andesitic
C. rhyolitic		D. pyroclastic
E. <None of the above>

35.	When does an object sink in water?
a.	When it has a greater density than water
b.	When water’s density is greater
c.	When its density equals the density of water
d.	<None of the above>

36.	What formula is used to find if an object is buoyant in water?
	a. Density = volume/ mass
	b. Density = mass/ volume
	c. Mass = volume/ density
	d. <None of the above>

37. 	____________ nutrients consist of calcium, iron, or potassium.
a.	Organic			b.	Inorganic
c. 	Molecular			d.	Fatty
e.	<None of the above>

38. 	A Calorie is ____________ a calorie.
a.	a thousand times greater than
b.	a thousand times less than
c. 	the same as
	d.	not a unit of energy like
e.	<None of the above>

39. 	The most common cause of waves is the ___________.
	a. tides			b. wind
	c. coriolis force	d. rain
	e. <None of the above>

40. 	Irregular patterns of waves with peaks in the same area of the wind waves are ____________.
	A. Sea	B. Swell     C. Breaker    D. Crest  

41.	The electrical devices in our homes use __________
a.	static electricity		b.	electromagnetism
c.	current electricity		d.	<None of the above>

42. 	____________ make up electric current when they flow through objects like wires and light bulbs
a.	protons		b.	neutrons
c.	electrons		d.	ions