Kinetic friction on an incline problem

AI Thread Summary
The problem involves a mountain climber lowering himself down a cliff while tied to a rock, with the rope passing over a frictionless pulley. The climber drops 10 meters in 6.2 seconds, and the task is to determine his acceleration and the coefficient of kinetic friction between the rock and the incline. To find the climber's acceleration, apply kinematic equations assuming constant acceleration. After calculating the acceleration, the force exerted by the rock on the climber can be determined, which will lead to finding the coefficient of friction. Clarification on the incline's angle and pulley position is necessary for a complete understanding of the setup.
-Justin-
Messages
3
Reaction score
0
Hey guys this question has been stumping me to death! Any help at all would be greatly appreciated.

A mountain climber has tied himself to a rock and has begun to lower himself down a cliff. The rope passes over a frictionless pulley. At time t=0, the rock and the mountain climber are not moving, the mountain climber drops 10 meters in 6.2 seconds. The mass of the climber is 70kg, and the mass of the rock is 500kg. The mountain climber is directly vertical and the rock is sitting at 15 degrees above the x-axis.
What is the mountain climber's acceleration while he drops? Assume it is a constant acceleration.
Find the coefficient of kinetic friction between the rock and the side of the mountain.
 
Physics news on Phys.org
I don't really understand the problem. Is the cliff also inclined at 15 degrees above the x-axis (doubtful!)? Where is the pulley? Where is the rock? A diagram would be helpful.
 
here is a picture of the drawing.

click either one of the links
http://img.photobucket.com/albums/v201/b16eh2/cc93d412.jpg
 

Attachments

  • DSCF3029 (WinCE).JPG
    DSCF3029 (WinCE).JPG
    4.5 KB · Views: 502
Last edited by a moderator:
For the first question, since you're told to assume constant acceleration, the question becomes a simple kinematics question. At t = 0, u = 0. At t = 6.2s, s = 10m. Apply your kinematics equation.

With the first part, you can get the acceleration of the mountain climber. Then, you should next find out the force the rock exerts on the climber, and from there you can find out the coefficient of friction.
 
Thread 'Collision of a bullet on a rod-string system: query'
In this question, I have a question. I am NOT trying to solve it, but it is just a conceptual question. Consider the point on the rod, which connects the string and the rod. My question: just before and after the collision, is ANGULAR momentum CONSERVED about this point? Lets call the point which connects the string and rod as P. Why am I asking this? : it is clear from the scenario that the point of concern, which connects the string and the rod, moves in a circular path due to the string...
Back
Top