Greetings!
The conclusion is:
The return trip will take 18 hours.
Reasoning:
To determine the duration of the return journey, we must calculate the distance from the destination back to the starting point.
The ship travels at 15 miles per hour (mph) over 6 hours, yielding a distance of:

The distance from the starting point to the destination is 90 miles, and for the return trip, the motor operates at a speed of 5 mph. Thus, computing the time taken gives us:

Consequently, the return trip will take 18 hours to complete.
Have a nice day!
The tension does not approach infinity.
<span>Let's analyze free body diagrams (FBDs) for each mass, considering the direction of motion of m₁ as positive.
For m₁: m₁*g - T = m₁*a
For m₂: T - m₂*g = m₂*a
Assuming a massless cord and pulley without friction, the accelerations are the same.
From the second equation: a = (T - m₂*g) / m₂
Substitute into the first:
m₁*g - T = m₁ * [(T - m₂*g) / m₂]
Rearranging:
m₁*g - T = (m₁*T)/m₂ - m₁*g
2*m₁*g = T * (1 + m₁/m₂)
2*m₁*m₂*g = T * (m₂ + m₁)
T = (2*m₁*m₂*g) / (m₂ + m₁)
Taking the limit as m₁ approaches infinity:
T = 2*m₂*g
This aligns with intuition since the greatest acceleration m₁ can have is -g. The cord then accelerates m₂ upward at g while gravity acts downward, leading to a maximum upward acceleration of 2*g for m₁.</span>
Option D is indeed correct, as it ensures that the post's point is equidistant from the ground, maintaining a perpendicular angle at two points on the surface.
Answer:
Robyn's model is logical, while Mark's is illogical.
Step-by-step explanation:
This question doesn't require calculations. What we need to do is analyze each model logically.
Mark's
Mark's representation indicates 20 instead of 2, which signifies that 200 is ten times greater than 20, making it nonsensical.
Robyn's
Robyn's representation displays 2, suggesting that 200 is 100 times greater than 2, which is not only accurate but also reasonable since 100 * 2 equals 200.