An electric device delivers a current of [tex]$15.0 A$[/tex] for 30 seconds. How many electrons flow through it?
Answer (2)
Rock A experiences temperature fluctuations and intermittent rain, leading to expansion and contraction, which causes fractures.
Rock B is exposed to acidic showers, altering its chemical composition.
Rock C is covered with algae and lichen, causing only surface changes.
Rock D is in an oxygen-rich environment, leading to oxidation and changes in chemical composition.
Rock E is in a hot and dry environment, causing weathering but less likely to cause fractures.
Therefore, Rock A is the most likely to develop fractures without significant chemical changes: A .
Explanation
Understanding the Problem We are given five rocks (A, B, C, D, E) placed in different environments. We need to determine which rock most likely developed large fractures and split into two pieces while maintaining a largely unchanged chemical composition.
Analyzing Rock A's Environment Rock A is exposed to intermittent rain showers and temperatures alternating between − 2 ∘ C and 2 0 ∘ C . The temperature fluctuations can cause the rock to expand and contract, leading to fractures. The intermittent rain showers can exacerbate this process. The chemical composition is less likely to change significantly.
Analyzing Rock B's Environment Rock B is exposed to frequent acidic showers containing carbonic acid. The acidic environment would likely alter the chemical composition of the rock through chemical reactions.
Analyzing Rock C's Environment Rock C is covered with algae and lichen. Algae and lichen might cause some surface changes, but are unlikely to cause large fractures or significant changes in the overall chemical composition.
Analyzing Rock D's Environment Rock D is placed in an oxygen-rich environment. An oxygen-rich environment could lead to oxidation reactions, potentially altering the chemical composition.
Analyzing Rock E's Environment Rock E is in a hot and dry environment with a low temperature of 3 5 ∘ C . This environment might cause some weathering, but is less likely to cause large fractures compared to temperature fluctuations. The chemical composition might change slightly due to dehydration.
Determining the Most Likely Rock Comparing the potential impacts of each environment, Rock A's environment is most likely to cause fractures due to temperature fluctuations without significantly altering the chemical composition.
Conclusion Therefore, the rock that most likely fits the description is Rock A.
Examples
Consider bridges and roads. During winter, water seeps into small cracks, freezes, and expands. This expansion widens the cracks, eventually leading to significant damage. This process, similar to what happened to Rock A, is called frost weathering and is a major cause of infrastructure deterioration in cold climates. Understanding these weathering processes helps engineers design more durable structures.
Approximately 2.81 × 10²¹ electrons flow through the electric device delivering a current of 15.0 A for 30 seconds. This is calculated by first determining the total charge using the formula Q = I × t, then finding the number of electrons by dividing the charge by the charge of a single electron. Thus, a large number of electrons pass through the device during this time period.
;
