Why does Harry's vacation start early?

[parker21]

Harry the painter swings year after year from his bosun's chair. His weight is 500 N and the rope, unknown to him, has a breaking point of 300 N. Why doesn't the rope break when he is supported as shown to the left below? One day Harry is painting near a flagpole, and, for a change, he ties the free end of the rope to the flagpole instead of to his chair as shown to the right. Why did Harry end up taking his vacation early?


. How does the direction of a friction force compare with the velocity of a sliding object?

 

[Andrew Mason]

Harry the painter swings year after year from his bosun's chair. His weight is 500 N and the rope, unknown to him, has a breaking point of 300 N. Why doesn't the rope break when he is supported as shown to the left below? One day Harry is painting near a flagpole, and, for a change, he ties the free end of the rope to the flagpole instead of to his chair as shown to the right. Why did Harry end up taking his vacation early?


. How does the direction of a friction force compare with the velocity of a sliding object?

I don't know where your diagram is but I suspect that in the first case the rope is hooked over something and connects to the chair in two places (in which case, each holding so it can support 600 N) and in the second case he just has one piece of rope which breaks when he puts 500 N force on it.

AM

 

[Chi Meson]

AM you are insightful. This is question 34 from chapter 4 of Paul Hewitt's Conceptual Physics text. And your assumption is correct.

Parker21: there is no friction in this problem (at least it is not significant) and you do not compare forces with velocities, and anyway nothing is sliding since this is a "static equilibrium" problem. Read your textbook section 4.7 .