View Single Post
  #2   Report Post  
posted to alt.sailing.asa
Walt Walt is offline
external usenet poster
 
First recorded activity by BoatBanter: Jul 2006
Posts: 348
Default Rope and Block Question #1

Bart wrote:

A load on the line is 1000 lbs.

You have just lead a line through a block, around
an angle of 180 degrees. What is the load on the
sheave? [1 pt]


2000 lbs.

For an angle of 90 degrees, what would be the load on
the sheave? [1 pt]


2 x load x cos(angle/2) = 2000 cos(45) = 2000(.707) = 1,414 pounds

At what angle does the sheave load match the line load?
[1 pt]


Load = 2 x load x cos(angle/2)

cos(angle/2) = 1/2

angle = 2 inv_cos(1/2) = 2 * 60 = 120 degrees or pi/3 radians.


//Walt