A rolling freight car crashes into a twice-as-heavy freight car at rest. After coupling they roll with a speed of 2 m/s. From this information the initial speed of the lighter freight car was
A. 8 m/s
B. 5 m/s
C. 4 m/s
D. 6 m/s
Answer: D
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Over time, as your instructor eats the candies, which of the following statements is (are) true? Circle all that apply
a) There are now more yellow than red candies left in the bag b) There are now more red than yellow candies left in the bag c) The red candies are depleted (eaten) twice as fast as the yellow candies d) The yellow candies are depleted (eaten) twice as fast as the red candies
Which of the following statements about our global food supply is true?
A) We currently have a deficit in our global food supply, and the deficit is expected to worsen over the next 40 years. B) New developments in organic farming and genetically modified crops are expected to relieve our current deficit in global food supply. C) To avoid a deficit in our global food supply, food production will have to increase faster over the next 40 years than it has over the past 40 years. D) The surplus in our global food supply is expected to provide us with a "cushion" as our global population increases to 9 billion people by the middle of the 21st century.
The most common use of bioremediation has been to assist in the cleanup of ________
A) PCBs B) heavy metal contamination sites C) herbicide and pesticide over-application D) non-biodegradable chemicals E) oil spills
One major reason why lakes and marshes are common in recently glaciated areas is because:
a. those areas have very humid climates. b. a huge amount of water was released by the melting of the ice. c. the glaciers carved dendritic stream systems. d. when the ice disappeared, sea level dropped, leaving much standing water stranded on the land. e. preexisting drainage was reshaped and blocked by glacial erosion and deposition.