Calculating Terminal Velocity for Parachute Design

Click For Summary

Discussion Overview

The discussion focuses on calculating terminal velocity in the context of parachute design for a physics project. Participants explore methods for measuring terminal velocity, the relationship between surface area and terminal velocity, and practical experimental setups.

Discussion Character

  • Exploratory
  • Technical explanation
  • Homework-related

Main Points Raised

  • One participant describes their experimental setup using coffee filters and string, expressing uncertainty about calculating terminal velocity.
  • Another participant suggests using data loggers and motion sensors for accuracy but also offers the stopwatch method as an alternative, noting potential high percentage uncertainty due to human reaction time.
  • A different participant shares their experience with a successful A2 project, detailing the use of refuse sacks for parachutes and timing the drop from a height to estimate terminal velocity.
  • One participant seeks confirmation on their understanding of using a video camera to analyze the parachute's motion and the need to establish a mathematical relationship between surface area and terminal velocity.
  • A later reply affirms the participant's approach, stating that a good parachute design should reach terminal velocity quickly.

Areas of Agreement / Disagreement

Participants express various methods for measuring terminal velocity and discuss the relationship between surface area and terminal velocity. There is no consensus on a single method or formula, and some uncertainty remains regarding the best approach to establish the mathematical relationship required.

Contextual Notes

Participants mention different experimental setups and methods, indicating potential limitations in accuracy and the influence of human factors on timing measurements. The discussion does not resolve these limitations or provide a definitive mathematical relationship.

Who May Find This Useful

Students and educators involved in physics projects related to motion, terminal velocity, and experimental design may find this discussion relevant.

whisperblade
Messages
11
Reaction score
0
This is my first time posting here but i need some serious help.

I'm in the process of doing a physics project right now, and I decided to relate the surface area of an object to its terminal velocity. I know how I am going to set up this experiment using coffee filters and string and a set weight to make sure the parachute goes down straight and all, but I'm at a loss at how to calculate the terminal velocity of the object. can someone please help!
 
Physics news on Phys.org
Most of the similar experiments I've seen is to use data loggers and motion sensors. That is the simplest way of finding the terminal velocity. However, if you don't have the luxury of such apparatus, you can always use the stopwatch method, measure the time taken over a vertical distance once the terminal velocity has been reached. The percentage uncertainty may be high due to human reaction time, but there are a few ways to reduce it. I leave it up to you to think of how that can be done.
 
We've done this succesfully as an A2 project. We used cut-down refuse sacks to make large parachutes. This way they fell slower and errors with timing by hand were minimised.

We dropped them down a four floor high stairwell. Terminal velocity was estimated as being reached by the time they had dropped one floor. Timing was from there to the ground.


A good investigation is to see what is the optimum size hole in the middle for slow and stable descent.
 
Well i understand to use the stopwatch method but let me know if I am setting this up right. My teacher refuses to help us.

I got the parachute things set up. And a set vertical height i can drop from. I am going to use a video camera to help play out the falling motion too. To calculate terminal velocity I basically find the velocity when i see that the parachute is traveling at a constant speed. But the thing is, on the syllabus I have it says i need to find a mathmatical relationship. So would that mean that I need to somehow relate surface area to the terminal velocity of the object.
 
Yes. What you say above sounds correct.

A good parachute design should hit terminal velocity pretty quickly.
 

Similar threads

High School Direction of Resultant Force on a Skydiver After Opening Parachute
  • · Replies 6 ·
Replies
6
Views
3K
High School Terminal Velocity Equation in vertical cylinder with some fluid
  • · Replies 2 ·
Replies
2
Views
2K
High School Terminal Velocity: Student Investigation & Incorrect Book Answer
  • · Replies 9 ·
Replies
9
Views
3K
Undergrad Effect of vent ratio on the drag coefficient of round parachutes
  • · Replies 5 ·
Replies
5
Views
2K
Undergrad Increase in rising air bubble's terminal velocity
  • · Replies 3 ·
Replies
3
Views
2K
Undergrad Collision when a falling tank impacts the surface of a lake
  • · Replies 7 ·
Replies
7
Views
3K
Graduate Hyperbolic tangent function for terminal velocity with Vo>Vt
  • · Replies 3 ·
Replies
3
Views
3K
Undergrad How to calculate Drag Coefficient?
  • · Replies 26 ·
Replies
26
Views
15K
Graduate Penetration of falling object into sediment (after water)
  • · Replies 8 ·
Replies
8
Views
3K
Graduate Terminal Velocity of a Cylinder Freefalling Through a Fluid
  • · Replies 6 ·
Replies
6
Views
11K