Geologists Use Explosives to Map the Subterranean

question 163

Multiple Choice

Geologists use explosives to map the subterranean. The times for the reflected waves to arrive at a monitoring station can tell a great deal about the composition of the rock structures. Suppose the time it takes for a wave that is reflected from the interface of 1) and 2) is 2 s, and the time for another wave that is reflected between 2) and 3) is 2.5 s, and the speed of the wave in layer 1) is 6 km/s and in layer 2) is 4 km/s, then how thick is layer 2) ?

• A) 2 km
• B) 1 km
• C) 3 km
• D) 6 km
• E) 8 km

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Definitions:

Allowance for Doubtful Accounts

A contra-asset account on a company's balance sheet that represents the estimated portion of accounts receivable that may not be collectible.

Allowance Method

An accounting technique that estimates and sets aside a portion of accounts receivable deemed uncollectible as an allowance for doubtful accounts.

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The sum of all assets expected to be converted into cash, sold, or consumed within one year or the normal operating cycle, whichever is longer.