Physical Science 101 Name_____________

Equations and constants:

E=hf v=l f T=1/f d=vt speed of light=3.0x10⁸ m/s

1. If both an empty and half full wine glasses are made to resonate which has the higher pitch? Which has the lower frequency?

 

2. Does sound travel faster or slower in moist air.

 

3. A boy places one speaker under water and another above the waters surface. His friend at the other side of the lake has one ear above water and one below. Through which ear does the boy hear sound from a speaker first?

 

4. An object is placed at a distance greater than the focal length but less than two times the focal length of a converging lens. Is the image real or virtual, inverted or upright, larger or smaller? Can you think of a piece of equipment that uses a lens in this fashion?

 

 

5. How does the V shape of shock wave depend on the speed of the source?

 

 

6. How can a single sheet of Polaroid film be used to show that light from the sky is partially polarized?

 

7. For a nearsighted eye, what is the proper type of corrective lens?

 

8. Which color of light travels the slowest through water?
9. The light that comes from a nearby galaxy named Andromeda is Doppler shifted towards the blue end of the spectrum. What does this tell us about the motion of Andromeda?

 

10. How should you arrange the polarization axes to minimize the glare from light reflected off a water surface?

 

11. Why does a star near the horizon appear higher than its actual position?

 

 

 

12. Why is the sky blue during daylight hours?
13. Why are breaking waves at the ocean white?

 

 

14. A sound wave and light wave both have the same wavelength. What can be said about the corresponding frequencies? Explain.

 

 

15. How could you determine if a distant star contained calcium?

 

 

16. A sound that is ten thousand times more intense than a barely audible sound (0 dB) will have an intensity of how many dB?

 

17. White light shinning on a prism disperses the white light into the colors of the rainbow. Does red or blue light refract more? Why?

 

 

18. For standing waves on a bungee cord, as the frequency increases, what happens to the wavelength and speed of the wave?

 

19. Name two ways of altering a guitar string to increase the speed of a wave along the sting.

 

 

20. Recall that the range for normal human hearing is between 20 Hz and 20,000 Hz. For sound waves in air traveling at 340 m/s, what is the longest wavelength our ears can detect?

 

 

 

21. In which medium does sound travel faster, air or solids?

 

22. Do the photons of red light or blue light carry the most energy? Does the energy of a photon depend on wavelength?

 

 

23. Sketch the wave display on an oscilloscope for a quiet, high pitch note versus a loud, low pitch not. Be sure to label which is which.

 

 

 

 

 

24. A guitar string is slightly out of tune and vibrates at a frequency of 250 Hz. What is the beat frequency when it is struck at the same time as another string which vibrates at 256 Hz? Is this beat audible?
25. What is the resulting color transmitted when white light is incident on a combination of yellow and blue filters?

 

26. What type of photoreceptor is found principally at the fovea and what is one of its main functions?

 

27. If you shine yellow light onto a yellow car, what color will it be?

 

28. Sketch two eyes, a nose, two ears and the blind spot in our eyes for a view looking down from above towards the top of somebody’s head.

 

 

 

 

29. When white light shines on the ocean why does it appear to be cyan?

 

 

30. A bungee cord of length 400 cm oscillates in its 4^th harmonic. What is the wavelength of the standing waves?

 

31. Compare a converging (concave) mirror and a diverging (convex) mirror. Make a sketch of each (label), show what happens when parallel rays of light are incident onto each, and compare the images produced by each.

 

 

 

 

 

 

32. With the aid of a sketch, explain what is happening to produce magenta colored light when we look at a thin layer of oil on water. Why do we see other colors when we look at other places on the oil?

 

 

 

 

 

 

33. Compare longitudinal and transverse waves. Describe the characteristics of each and sketch. Name an example of each type of wave.

 

 

 

 

 

34. A tuning fork emits sound with a wavelength of 1m. If it is placed at the open end of an adjustable tube with the other end submerged in water. What is the shortest length of the tube for which its air column will resonate?

 

35. A bat flying in a cave emits a sound and receives its echo 1s later. How far away is the cave wall? You may use 340 m/s for the speed of sound.

 

 

 

 

36. An object is placed less than a focal lengths distance of a converging lens. Is the image real or virtual, inverted or upright, larger or smaller? What do we call a lens when we use it in this fashion?

 

 

37. If a bell is ringing inside a bell jar, we can no longer hear it when the air is pumped out, but we can still see it. What differences in the properties of sound and light does this indicate?

 

 

38. Explain the phenomena of resonance in terms of forcing frequency and natural frequency. State your favorite example of a resonance phenomena.

 

 

 

39. Why are the rules for adding colored pigments different than the rules for adding colored light?

 

 

40. Light illuminates two closely spaced thin slits and produces an interference pattern on a screen behind. How will the distance between the fringes of the pattern differ for red light and blue light? Does red or blue light diffract more?

 

 

41. What happens to the distance between interference fringes in the above example if the two slits are moved closer together?

 

42. What is monochromatic light? Can you give an example of a monochromatic light source?

 

43. In class we observed an excited neon gas through a diffraction grating. What was happening in the neon atoms to produce light?

 

 

44. Does red or blue light diffract more when passing through a narrow slit?