Question

4 which of the following best explains what might have happened to trigger the explosive energy after the landslide, using the model you chose above? a the magnitude of the forces upward from the magma became larger (fp). the resul unbalanced forces upward from the magma transferred energy out of the system. b the magnitude of the forces downward from the weight of the crust (fw) became lar the resulting unbalanced forces downward transferred energy out of the system. c the magnitude of the forces upward from the magma became smaller (fp). the resul unbalanced forces downward transferred energy out of the system. d the magnitude of the forces downward from the weight of the crust (fw) became sma the resulting unbalanced forces upward from the magma (fp) transferred energy out the system.

Explanation:

To determine the correct answer, we analyze the forces involved in a landslide - magma system. After a landslide, the weight of the crust (Fw) likely decreases (since part of the crust has moved in the landslide). When Fw becomes smaller, the upward force from magma (FP) becomes unbalanced upward. Unbalanced upward forces from magma would transfer energy out of the system (leading to explosive energy, like in a volcanic - related event after a landslide).

• Option A: If FP becomes larger, unbalanced upward forces would transfer energy, but a landslide is more likely to reduce the downward force (Fw) rather than increase FP directly in this context.
• Option B: If Fw becomes larger, unbalanced downward forces would not lead to explosive energy from magma (explosive energy from magma is related to upward forces).
• Option C: If FP becomes smaller, unbalanced downward forces would not lead to explosive energy from magma.
• Option D: When Fw (downward force from crust weight) becomes smaller, the upward force from magma (FP) is unbalanced upward, and this unbalanced upward force transfers energy out of the system (causing explosive energy), which fits the scenario after a landslide (where part of the crust has moved, reducing Fw).

Answer:

D. The magnitude of the forces downward from the weight of the crust (Fw) became small. The resulting unbalanced forces upward from the magma (FP) transferred energy out of the system.