Designing a Buoy Tether: Force Analysis and Excel Spreadsheet Solution

  • Thread starter Thread starter Shnitzel
  • Start date Start date
  • Tags Tags
    Designing
Click For Summary
SUMMARY

The discussion focuses on designing a buoy tether system, specifically a vertical right circular cylinder buoy with an outside diameter of 8 feet and a height of 12 feet, made from glass-fiber-reinforced plastic (FRP) with a thickness of ½ inch. The buoy is tethered by an 80-foot cable, which is designed to snap if the water depth exceeds 90 feet. Key calculations involve applying Archimedes' Principle to determine the force on the cable at varying river depths, with an example provided for a depth of 85 feet to illustrate the tension on the buoy cable.

PREREQUISITES
  • Understanding of Archimedes' Principle
  • Basic knowledge of force balance calculations
  • Proficiency in Microsoft Excel for data analysis
  • Familiarity with buoyancy concepts and gravitational force
NEXT STEPS
  • Learn how to implement Archimedes' Principle in Excel for buoyancy calculations
  • Research force balance equations relevant to buoy systems
  • Explore Excel functions for calculating tension and force at varying depths
  • Study the properties of glass-fiber-reinforced plastic (FRP) and its implications on buoy design
USEFUL FOR

Students in physics or engineering, marine designers, and anyone involved in buoy design and tethering systems will benefit from this discussion.

Shnitzel
Messages
1
Reaction score
0

Homework Statement


Consider a buoy in the form of a vertical right circular cylinder of outside diameter (D) of 8 feet, and
height (H) of 12 feet. The buoy is a hollow cylinder formed of glass-fiber-reinforced plastic (FRP)
that is ½-inch thick. The buoy is to be placed in a large river and tethered to the bottom by a cable
that is 80 feet long
The cable is supposed to snap if the water depth exceeds 90 feet. Set up an
Excel spreadsheet to compute the force on the cable at different river depths and the force at which
the cable should be designed to snap.


Homework Equations


Archimedes Pinciple: mass of obj- apparent mass of obj= Density of water * vol of obj
The force on the cable can be computed from a force balance on the buoy.
The downward force due to gravity is the total mass of the buoy multiplied by gravitational
acceleration

The Attempt at a Solution


Not sure how to start this, I have to solve it in excel but don't know where to begin
 
Physics news on Phys.org
Shnitzel said:

Homework Statement


Consider a buoy in the form of a vertical right circular cylinder of outside diameter (D) of 8 feet, and
height (H) of 12 feet. The buoy is a hollow cylinder formed of glass-fiber-reinforced plastic (FRP)
that is ½-inch thick. The buoy is to be placed in a large river and tethered to the bottom by a cable
that is 80 feet long
The cable is supposed to snap if the water depth exceeds 90 feet. Set up an
Excel spreadsheet to compute the force on the cable at different river depths and the force at which
the cable should be designed to snap.


Homework Equations


Archimedes Pinciple: mass of obj- apparent mass of obj= Density of water * vol of obj
The force on the cable can be computed from a force balance on the buoy.
The downward force due to gravity is the total mass of the buoy multiplied by gravitational
acceleration

The Attempt at a Solution


Not sure how to start this, I have to solve it in excel but don't know where to begin

Hi Shnitzel, Welcome to Physics Forums.

To start off, why not perform the calculation by hand for one particular case. That will at least tell you what constants, variables and formulas you'll need to implement.

So, suppose that at some time the river is 85 feet deep. What's the tension on the buoy cable?
 

Similar threads

What is the optimal design for a buoy tether in a large river?
  • · Replies 2 ·
Replies
2
Views
2K