#7 - The mu mesons generated by cosmic rays just outside

[Administrator]

Complete Question Explanation

Must Be True, Fill in the Blank. The correct answer choice is (D).

Answer choice (A):

Answer choice (B):

Answer choice (C):

Answer choice (D): This is the correct answer choice.

Answer choice (E):

This explanation is still in progress. Please post any questions below!

[ero225]

Can you please explain why answer D is correct?

[Luke Haqq]

Hi ero225!

To understand why (D) is correct, take the conclusion of the stimulus: "Apparently, mu mesons moving at speeds near the speed of light __________."

The "apparently" is referring to what is apparent from the previous sentence, which describes a phenomenon: "If mu mesons traveling through the atmosphere at speeds approaching the speed of light typically decay as fast as they do in the laboratory, then we should detect only about one one-hundredth of the number we actually do detect." In this sentence, the reference to what "we actually do detect" is key. We know that the laboratory speed of decay is quicker, and that we'd detect a much smaller percentage of atmospheric mu mesons if they decayed at that rate. Since we actually do detect more, we can conclude that the atmospheric mu mesons decay at a slower rate than the mu mesons in laboratories, which are "nearly at rest." This is reflected in answer choice (D), the mentioned mu mesons "decay more slowly than mu mesons almost at rest."

[pointedsmock]

Hi ero225!

To understand why (D) is correct, take the conclusion of the stimulus: "Apparently, mu mesons moving at speeds near the speed of light __________."

The "apparently" is referring to what is apparent from the previous sentence, which describes a phenomenon: "If mu mesons traveling through the atmosphere at speeds approaching the speed of light typically decay as fast as they do in the laboratory, then we should detect only about one one-hundredth of the number we actually do detect." In this sentence, the reference to what "we actually do detect" is key. We know that the laboratory speed of decay is quicker, and that we'd detect a much smaller percentage of atmospheric mu mesons if they decayed at that rate. Since we actually do detect more, we can conclude that the atmospheric mu mesons decay at a slower rate than the mu mesons in laboratories, which are "nearly at rest." This is reflected in answer choice (D), the mentioned mu mesons "decay more slowly than mu mesons almost at rest."

Thank you for the detailed explanation. I'm still a bit confused about answer C. It also refers to the faster decay rate of mu mesons in the laboratory than in the atmosphere. Why is C not the correct answer?