#19 - Geologist: As a spinning object’s radius decreases, its

[Administrator]

Complete Question Explanation

Weaken. The correct answer choice is (B).

Answer choice (A):

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

Answer choice (C):

Answer choice (D):

Answer choice (E):

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

[Claire.L]

Hello!

Could you please explain why D is correct and the others are incorrect? Especially why A is incorrect? Thank you!

[Dana D]

Hey Claire,

The geologists argument is that the earth's rate of rotation has increased due to the increased number and severity of earthquakes in the past decade, because the earthquakes are reducing the Earth's radius. To weaken this argument, we need to weaken this cause and effect relationship.

Earthquakes decreased radius increased rate of rotation

Answer choice (A) strengthens the geologists argument, providing additional support for the idea that more earthquakes = smaller radius, which according to the geologist means raster rotation.

Answer (B) is correct, because it introduces a possible alternative cause for the increased rate of rotation and shows that one of the causes (earthquakes) may occur without the effect (a decreased radius)

Answer (C) is irrelevant, because even if this were true it does not change the underlying principle that smaller radius = faster rotation.

Answer choice (D) doesn't weaken the argument - even if the rate of rotation has fluctuated across history, it could still be true that modern Earth has a smaller radius and the rate of rotation is now faster overall than it was historically.

Answer (E) just provides more support for the idea that tectonic plates are moving, which does not negate the argument that earthquakes are causing them to move towards the center of the earth and decreasing the radius of the planet overall.