Calculating Projectile Force from Rotational Velocity of a Throwing Sling

  • Context: Undergrad 
  • Thread starter Thread starter Riley Werling
  • Start date Start date
  • Tags Tags
    Mechanics
Click For Summary

Discussion Overview

The discussion revolves around calculating the rotational velocity of a sling and using that information to determine the force exerted by a projectile launched from the sling. The scope includes practical application and mathematical reasoning related to projectile motion and rotational dynamics.

Discussion Character

  • Exploratory
  • Technical explanation
  • Mathematical reasoning

Main Points Raised

  • One participant seeks guidance on determining the rotational velocity of a sling and its relation to projectile force, expressing difficulty in understanding existing resources.
  • Another participant clarifies that the whirling speed is influenced by the user's choice and is a function of the effective length of the sling and the rotational speed.
  • It is suggested that the center of rotation can be assumed to be at the shoulder, with considerations for the arm's position.
  • A participant inquires about the effective length of the sling and the user's ability to whirl it, prompting further exploration of the user's arm speed.
  • Participants propose measuring the number of rotations made in a minute or a shorter duration to estimate the whirling speed.
  • One participant calculates the rotational speed in revolutions per second and introduces a formula for determining the speed of the sling pouch based on its effective length.

Areas of Agreement / Disagreement

Participants generally agree on the need to measure the user's whirling speed and the effective length of the sling, but there is no consensus on specific values or methods for calculating the projectile force.

Contextual Notes

Limitations include the lack of specific measurements for the user's arm speed and the effective length of the sling, as well as the absence of a clear method for translating rotational velocity into projectile force.

Who May Find This Useful

This discussion may be useful for individuals interested in the mechanics of projectile motion, particularly in the context of using slings or similar devices for launching projectiles.

Riley Werling
Hey, I am not sure if this should be posted somewhere else, if so if you could direct me it would be much appreciated. So my question is how would i find the rotational velocity of a sling and how i could use that to calculate the force of a projectile from said sling. I've tried doing some research online but most of what I've read is way over my head so i was hoping someone here might be able to help me.

Thanks for any and all help you guys provide.
 
Physics news on Phys.org
I assume that you are talking about a real sling - that is two thongs and a pouch which are whirled around until one of the thongs is released and the projectile flies free ?

The whirling speed is really determined by choice by the person using the sling . The speed picked up by the projectile is a simple function of the whirling speed and the effective length of the sling .

The effective length of the sling is the length of the thongs plus some additional length from your arms .

So how fast (rpm) can you whirl a sling and what is the effective length of your sling ?
 
Last edited:
Hint : For simplicity you can assume that the centre of rotation for the whirling is at you shoulder . Remember that your arms will most likely be bent .
 
So how fast (rpm) can you whirl a sling and what is the effective length of your sling ?[/QUOTE]
Sling would be 48in long and idek what rpm would be.. can't find an average anywhere online socichave no clue
 
How fast can you whirl your arms around ?
 
Pretty fast, if youre asking for a number i couldn't tell you
 
  • Like
Likes   Reactions: sophiecentaur
Whirl you arm as fast as possible and count the number of rotations made in a minute or if you can't manage a complete minute try thirty seconds .
 
Nidum said:
Whirl you arm as fast as possible and count the number of rotations made in a minute or if you can't manage a complete minute try thirty seconds .
100
 
So 100 turns in 1 minute or 100 rpm . Good .

100/minute is 100/60 = 1.67 revs/second .

The speed of the sling pouch as it goes around in a circle is given by 2 * pi * L * (revs/second) where L is the effective length of the sling .

L= 48 inches but we'll convert that to metres for our calculations . So we'll use L = 1.2 metres .

Do you want to try working out the pouch speed ?
 

Similar threads

Undergrad Tangential velocity of an object rotating around a rotating axis
  • · Replies 5 ·
Replies
5
Views
2K
Undergrad If we throw a ball with initial velocity v0, is there a force?
  • · Replies 3 ·
Replies
3
Views
2K
High School The physics of flywheel launchers (like tennis ball shooters)
  • · Replies 60 ·
3
Replies
60
Views
6K
Undergrad Excel projectile trajectory
  • · Replies 6 ·
Replies
6
Views
2K
Undergrad Confusion about adding angular velocities
  • · Replies 4 ·
Replies
4
Views
2K
Undergrad Does a rotating accelerometer moving linearly measure linear velocity?
  • · Replies 47 ·
2
Replies
47
Views
5K
Undergrad How Does Angular Velocity Affect Instantaneous Acceleration in Rotating Systems?
  • · Replies 1 ·
Replies
1
Views
1K
Undergrad Projectile Intercept Math & Trigonometry
  • · Replies 4 ·
Replies
4
Views
2K
Undergrad Coriolis acceleration of a projectile launched at the equator
  • · Replies 4 ·
Replies
4
Views
2K
Undergrad Calculate the Resultant Force Between 4 Points
  • · Replies 3 ·
Replies
3
Views
2K