consider a shale-free, dry, sandstone core plug. by measurement, the following data are known: d=254 cm, l= 6.00 cm, and mass (dry)=548 g. 1 knowing that the grain density of most sandstone is about 2.65 gm/cu. cm, estimate the porosity of the core plug. 2. the plug is completely saturated with 145,000-ppm nacl brine whose specific gravity is 1.1 the mass of the saturated core plug is now 60.38 g. calculate the porosity of the plug. 3. estimate the end-to-end resistance ofthe saturated core plug inohm at 80 degree fahrenheit. use chevron's formula for f when required. 4. by actual measurement, the end-to-end resistance of the plug is 83.3 ohm. calculate the ro value of the plug. 5. some of the brine is removed from the core plug: i. e, the core is partially desaturated. its mass now is 56.03 g. calculate the water saturation. 6. for anexponent n of 3, what would be the end-to-end resistance of the core?

19. explain why a magnet from your refrigerator could not be used to lift something as heavy as a car. (chapter 7 – pages 202-203) 20. can a magnet ever have a single pole? explain your answer. (chapter 7 – page 208) 21. what happens to the wavelength of a wave if the frequency is increased? (chapter 9 – pages 280-281) 22. an ocean wave has a wavelength of 10 m and a frequency of 4.0 hz. what is the velocity of the wave? show the appropriate equation from your book and show your work with units. (chapter 9 – page 282) 23. as you sit outside, the sound of a siren becomes lower in pitch. is the emergency vehicle moving away from or towards you? explain how you know. (chapter 10 – page 315-316) 24. why are two astronauts in space unable to hear one another? (chapter 10 – page 307) 25. explain in at least 3 sentences how electromagnetic waves form. (chapter 11 – page 338-339) 26. using the chart on page 345 in your textbook, what are the three types of electromagnetic wave with wavelengths shorter than those of visible light. give an example of each. (chapter 11 – pages 345-351) 27. explain why a leaf usually appears to be green, but a rose typically appears red. (chapter 12 – page 373) 28. what is the difference in light that is refracted compared to light that is reflected? think in terms of speed of light as well as what happens to light waves when they interact with a medium. (chapter 12 – pages 369-370) 29. how are concave and convex lenses different? (chapter 13 – page 408-410) 30. what type of mirror is used in rearview mirrors in cars? why is it important that these mirrors have the warning, “objects in mirror are closer than they appear.”? (chapter 13 – page 405)

Which statement is best supported by the information in the chart? wave y is moving the fastest. wave x is moving the fastest. all of the waves are moving at the same speed. all of the waves have the same value of wavelengths per second.

Listed below are the measured radiation absorption rates (in w/kg) corresponding to 11 cell phones. use the given data to construct a boxplot and identify the 5-number summary. 1.16 0.85 0.69 0.75 0.95 0.93 1.18 1.17 1.42 0.54 0.57 the 5-number summary is nothing, nothing, nothing, nothing, and nothing, all in w/kg. (use ascending order. type integers or decimals. do not round.)