Determining velocity for a pulley/rope system

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SUMMARY

The discussion focuses on calculating the final velocities of a crate and a crewman in a pulley/rope system during a slip incident. The crate, weighing 5.65 kg, is lowered at a constant speed of 1.50 m/s until it accelerates due to the crewman's slip on ice. The crewman, weighing 60.9 kg, experiences a loss of friction and is dragged toward the cliff edge. The relevant equations include Newton's Second Law (F = ma) and one-dimensional kinematics, which are essential for determining the final speeds of both the crate and the crewman upon reaching the ground.

PREREQUISITES
  • Understanding of Newton's Second Law (F = ma)
  • Familiarity with one-dimensional kinematics equations
  • Knowledge of free-body diagrams for analyzing forces
  • Concept of projectile motion in physics
NEXT STEPS
  • Calculate the acceleration of the crate after the crewman slips using Newton's Second Law.
  • Determine the final velocity of the crate just before it hits the ground using kinematic equations.
  • Analyze the forces acting on the crewman to find his acceleration and final velocity upon reaching the bottom of the ravine.
  • Explore the implications of frictionless surfaces in physics problems and their effects on motion.
USEFUL FOR

Physics students, educators, and professionals involved in mechanics, particularly those interested in dynamics and motion analysis in pulley systems.

Katatatat
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The Question:
Using a simply pulley/rope system, a crewman on an Arctic expedition is trying to lower a 5.65-kg crate to the bottom of a steep ravine of height 23.9 meters. The 60.9-kg crewman is walking along holding the rope, being careful to lower the crate at a constant speed of 1.50 m/s. Unfortunately, when the crate reaches a point 13.3 meters above the ground, the crewman steps on a slick patch of ice and slips. The crate immediately accelerates toward the ground, dragging the hapless crewman across the ice and toward the edge of the cliff.

If we assume the ice is perfectly slick (that is, no friction between the crewman and the ice once he slips and falls down), at what speed will the crate hit the ground? Assume also that the rope is long enough to allow the crate to hit the ground before the crewman slides over the side of the cliff. At what speed will the crewman hit the bottom of the ravine?​
The Relevant Equations:
F = ma
Equations for one-dimensional kinematics​
The Attempt:
I've looked at the forces for the crewman and crate separately with free-body diagrams, applying Newton's Second Law and using the following formulas to solve for acceleration, although I'm not entirely sure that is correct:
T - m1g = m1a
m2g - T = m2a​
As for the kinematics portion of the question, I assume the crate will follow a simple one-dimensional formula, while the crewman will have a projectile motion.​
 
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Welcome to PF;
The equations are not correct. There are 3 forces on the crewman.
Which direction does the crewman's weight act?

As for the kinematics... don't assume: the problem tells you what sort of motion to expect.
 

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