Final answer:
The scenario provided suggests an unrealistic average velocity for a mountain stream that exceeds physical limitations, revealing inconsistencies in the premises about stream capacity and flow rate.
Step-by-step explanation:
The question is asking about the capacity and flow characteristics of a mountain stream compared to a broad, slow moving river. To answer this, let's consider a scenario mentioned where a mountain stream is 10.0 m wide and averages 2.00 m in depth with a flow of 100,000 m³/s during spring runoff. To find the average velocity of the stream, we use the equation for flow rate (Q), which is Q = A×v, where A is the cross-sectional area and v is the velocity. Thus, v = Q/A.
(a) The cross-sectional area (A) of the stream is 10.0 m × 2.00 m = 20.0 m². The flow rate (Q) is 100,000 m³/s. Therefore, the average velocity (v) = 100,000 m³/s ÷ 20.0 m² = 5,000 m/s.
(b) An average velocity of 5,000 m/s is unreasonable because it is faster than the speed of sound and streams do not flow at such high speeds.
(c) The premises are unreasonable or inconsistent because a flow rate of 100,000 m³/s with a 10.0 m wide and 2.00 m deep stream is not physically possible under normal Earth conditions. This is evident in the unrealistic calculated velocity.