Points Earned: 0/1 Correct Answer: E Your Response: D
4. Stephanie and Topher are standing next to the Colorado River in the Grand Canyon. What can be said of the water here? A. The river was naturally muddy, but has been made clear because most of the sediment is settling out in the reservoir behind the dam upstream. B. The river was cleaned up briefly by the Park Service to help Stephanie and Topher in their filming. C. The river water is naturally clear, fed by snowmelt from the Colorado Rockies. D. The river is really filled with 7-UP, hence the green color. E. The river water is kept clear by the Park Service to keep the trout healthy. Native species that lived in the muddy waters are now in danger of becoming extinct, because the clear water released from the dam makes those fish too easy for predators to see. Points Earned: 1/1 Correct Answer: A Your Response: A 5. Given what you were told in class and the textbook about the formation of caves, it is likely that most large caves are formed: A. In limestone in moist climates. B. In sandstone in dry climates. C. In limestone in dry climates. D. In sandstone in moist climates.
E. In granites under Diet Pepsi. Caves require easily dissolved rock, and water to dissolve that rock. In really dry climates, limestone is a resistant rock that stands in huge cliffs. In wet climates, limestone dissolves to yield caves. Sandstone is not a good cave-former because sandstone does not dissolve easily. (Yes, there are very shallow rock-shelter caves in sandstone, which is why the question specifically notes “large caves”.) And while Diet Pepsi actually would be marvelous at dissolving limestone, Diet Pepsi attacks granite rather slowly and won’t make caves well. Points Earned: 0/1 Correct Answer: A Your Response: D Continue Contact Penn State ANGEL Support ©2006 ANGEL Learning, Inc. All rights reserved. ---------------- Forwarded Message ---------------- From: "MICHAEL STEPHEN MASER" <[email protected]> Date: Thu, Oct 16, 2008 04:41 PM Subject: shose To: [email protected] RockOn #6 Your response has been submitted successfully. Points Awarded 9 Points Missed 5 Percentage 64% 1. If all the water that falls on central Pennsylvania’s Happy Valley in a year as snow or rain stayed here as water without being used or evaporated, if spread uniformly over the land, it would make a layer about how thick? 0.003 feet. A. 0.03 feet. B. 30 feet. C.
3 feet. D. 0.3 feet. E. A typical rainfall supplies about an inch of water, or just under 0.1 foot. 30 feet of rain would be a big storm every day, about equal to the wettest place on Earth, and while sometimes it may seem our rain never ends, we really do have clear days. 0.3 feet is a mere 3 or 4 rainfalls per year, and is a dry desert. 0.03 feet would be the driest place on Earth, and 0.003 doesn’t occur on Earth. 3 feet is a nice number, and is correct.
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