# Q3 Benchmark Study Guide

1.  A spring stretches 14 cm when an object weighing 28 N is hung from it. What is the spring constant?

A  1.4´102 N/m

B  1.8´102 N/m

C  2.0´102 N/m

D  14´102 N/m

2.  A longitudinal wave with a wavelength of
0.50 m has a period of 0.20 s. How far does
the wave travel in 45 s?

A      6.8´101 m

B      1.1´102 m

C      1.4´102 m

D      1.7´102 m

Use the following illustration to answer problems 3 and 4.

3.  The illustration shows a spring stretched by the weight of a block. If the block weighs 34 N, what potential energy is stored in the spring?

A      2.0 J

B      2.8 J

C      3.5 J

D      4.1 J

4.  If the block were replaced with one that weighs 52 N, what would be the displacement?

A  17 cm

B  19 cm

C  21 cm

D  23 cm

5.  A wave reflects off a wall. Which of the following is true of the reflected wave?

A      The reflected wave has about the same amplitude as the incident wave and is inverted.

B  The reflected wave has a lesser amplitude than the incident wave and is inverted.

C  The reflected wave has a greater amplitude than the incident wave and is upright.

D      The reflected wave has about the same amplitude as the incident wave and is upright.

6.  Echoes are caused by the ____________ of sound waves off hard surfaces.

A  superposition

B  resonance

C  refraction

D  reflection

7.  The diagram shows the superposition of two waves. Which of the following is true about the waves shown in the diagram?

A  equal amplitudes, constructive  interference

B  equal amplitudes, destructive interference

C  different amplitudes, constructive interference

D  different amplitudes, destructive interference

8.   The velocity of sound is 343 m/s in air and
1493 m/s in water. For sound with a frequency of 440 Hz, what is the difference between the wavelength in air and in water?

A  1.0 m

B  2.6 m

C  4.2 m

D  4.4 m

9.   Two clarinet players are tuning their instruments. One plays a perfect G at 352 Hz. The other is slightly sharp and plays at 357 Hz. What is the beat frequency?

A  2.5 Hz

B  5 Hz

C  7.5 Hz

D  10 Hz

10. A 384-Hz tuning fork is held over a closed-pipe resonator. If the speed of the sound is 343 m/s, what is the spacing between the resonances?

A  0.223 m

B  0.447 m

C  0.670 m

D      0.893 m

11. A car approaches a pedestrian standing on the side of the road. The car is traveling at 24.2 m/s. The horn of the car emits a sound wave with a frequency of 482 Hz. What frequency is heard by the pedestrian?

A  478 Hz

B  490 Hz

C  519 Hz

D  522 Hz

12. The loudness of sound as perceived by the ear and brain depends mainly on its ___________.

A  Doppler effect

B  amplitude

C  velocity

D  pitch

13. As a train speeds away from a station, its whistle sounds with a frequency of 624 Hz. For a listener standing on the platform of the station, sound waves from the whistle have a frequency of 580 Hz. What is the velocity of the train relative to the listener at the station?

A    -23 m/s

B    -24 m/s

C      -25 m/s

D      -26 m/s

14. The wavelength of a beam of light passing through a vacuum is 420 nm. What is the frequency of the light beam?

A  6.7´1013 Hz

B  5.4´1014 Hz

C  7.1´1014 Hz

D  3.8´1014 Hz

15. The illustration shows a lamp and a candle illuminating a screen positioned between them. If the lamp is moved to a distance r = 1.02 m, how much brighter must the lightbulb be than the candle to have the same illuminance on the screen? A  1.5 times

B  3 times

C  4.5 times

D  9 times

16. If the luminous flux of a lightbulb is 1750 lm, what is the illuminance of a surface 2.0 m from the light source?

A  140 lx

B  35 lx

C  28 lx

D  13 lx

17. An architect is designing the lighting for a school. The illuminance in the classrooms must be at least 37 lx on students’ desks. If the light shining on each desk has a luminous flux of 4200 lm, how far above the desks should the lights be placed?

A      1.0 m

B      2.0 m

C      3.0 m

D      4.0 m

18. Light from a distant galaxy has an apparent wavelength of 452 nm. If the galaxy is known to be moving away at a speed of  what is the actual wavelength of the light?

A      377 nm

B      387 nm

C      527 nm

D      542 nm

19. If light passes from air into water at 40.0° to the normal, what is the angle of refraction? (The index of refraction for water is n = 1.33.)

A      28.9°

B  31.3°

C  58.7°

D  61.1°

20. Light passes from air into another medium at 30.0° to the normal. If the angle of refraction is 18.0°, what is the index of refraction of the new medium?

A  1.33

B  1.52

C  1.62

D  2.42

21. What happens when light enters a region with a higher index of refraction?

A  The light slows down and bends toward the normal.

B  The light speeds up and bends toward the normal.

C  The light slows down and bends away from the normal.

D  The light speeds up and bends away from the normal.

22. A light beam passes from flint glass
(n = 1.62) into ethanol (n = 1.36). What is the critical angle for total internal reflection of the light beam?

A      15.1°

B      26.0°

C      57.1°

D      84.0°

23.      Which expression equals the index of refraction of a given medium?

a. c/v

b.    v/c

c.     cvmedium

d.     vmediumc

24.  When light travels from one medium into a medium with a lower index of refraction, ____ .

a.     the speed of light increases

b.     the angle of refraction is smaller than the angle of incidence

c.     the refracted light bends toward the normal

d.     the angle of incidence equals the angle of refraction

25.  The index of refraction of the transparent mineral beryl is approximately 1.6. Transparent quartz has an index of 1.54. Diamond has an index of 2.42. Based on these facts, which statement is true? Assume light travels from air into each substance.

a.     All three minerals bend light to the same extent.

b.     Quartz bends light more than beryl does.

c.     Beryl bends light more than quartz does.

d.     Both beryl and quartz bend light more than diamond does.

# Science Fair Materials

Attention all Chemistry students!

Look below for the schedule of the Avance Science Fair and all the deadlines.  Due to copyright restrictions I can’t publish the science fair write up as an attachment so I’ll give out 1 copy to each group in class.

So far I’ve seen some very cool science projects ideas. Not just the out of book kind but extensions of the science fair to include other interesting and related information.

Here’s  the schedule.

 Status Due Date Things to do Monday 2/10 Choose topic and write project question. Wed 2/12 Get approval from your teacher. Fri    2/14 Research your topic and write key words and paragraph. Wed2/19 Write a hypothesis.Design an experiment; list variables and write procedure. Fri2/21 List and gather your materials. Week of 22/24-2/28 Conduct experiment and record data and observations. Create a table, chart, or graph of the data. Draw conclusions.Make the project display. Mon3/3 Write and print abstractTurn in planning packet to teacher. Thurs3/6 Present your project at the science fair.