Angle required to hit coordinates x, y, z with air ressitance

  • Context: High School 
  • Thread starter Thread starter TheShermanTanker
  • Start date Start date
  • Tags Tags
    Air Angle Coordinates
Click For Summary
SUMMARY

The discussion centers on calculating the launch angle required to hit specific coordinates (x, y, z) while considering air resistance. The formula provided is tan-1((v^2 +/- square-root(v^4 - g(gx^2 + 2yv^2)))/gx), which assumes only vertical resistance from gravity. However, the user is implementing a hard-coded air resistance value of 1% of the object's current velocity, applied every 1/20 of a second. The consensus is that integrating the equations of motion is necessary to accurately factor in air resistance.

PREREQUISITES
  • Understanding of projectile motion and kinematics
  • Familiarity with the concept of air resistance in physics
  • Basic knowledge of calculus for integrating equations of motion
  • Experience with numerical methods for solving differential equations
NEXT STEPS
  • Research "External Ballistics" to understand projectile motion in detail
  • Learn about numerical integration techniques for motion equations
  • Study drag models and their applications in physics simulations
  • Explore the effects of varying air resistance on projectile trajectories
USEFUL FOR

This discussion is beneficial for physicists, game developers, and engineers involved in projectile motion simulations, particularly those interested in incorporating realistic air resistance effects.

TheShermanTanker
Messages
13
Reaction score
4
The formula for the angle required for you to launch a projectile with a given velocity, gravity, distance and height difference is, taking g as gravity, v as total velocity, x as total distance on the horizontal plane and y as how high the target is above you (Negative value means the target is below you) is
tan-1((v^2 +/- square-root(v^4 - g(gx^2 + 2yv^2)))/gx). However, this assumes that the only resistive force is on the vertical plane (gravity) and that there is no horizontal resistance present (air resistance). However, the thing that I'm working on now has a hard-coded air resistance value of 1% of the object's current velocity that takes effect every 1/20 of a second (Basically imagine taking the object's velocity and multiplying it by 99% every twentieth of a second). Is there a way to factor air resistance in as well?
 
Physics news on Phys.org
Hello Tanker, ##\qquad## :welcome: ##\qquad## !

No analytic expression, I am afraid. So you have your numerical work (in the other thread) cut out for you :wink:

By the way, better not to call gravity force 'resisitive': it is a so-called conservative force: the work it does is converted into kinetic energy. For resisitive forces the work goes into heat and/or deformation.
 
  • Like
Likes   Reactions: TheShermanTanker
TheShermanTanker said:
Is there a way to factor air resistance in as well?
Have you been doing any reading about "External Ballistics"? https://en.wikipedia.org/wiki/External_ballistics

I'll also page @Dr. Courtney to see if he has better links or thoughts. :smile:

220px--Bullet_Wiki.ogv.jpg
 

Attachments

  • 220px--Bullet_Wiki.ogv.jpg
    220px--Bullet_Wiki.ogv.jpg
    4.7 KB · Views: 550
  • Like
Likes   Reactions: TheShermanTanker
No closed for solution. As mentioned above, the needed approach is to integrate the equations of motion.

But the drag model you are working with seems unusual and slightly contrived. It might work ok for relatively short flight times.
 
  • Like
Likes   Reactions: TheShermanTanker

Similar threads

  • · Replies 2 ·
Replies
2
Views
1K
  • · Replies 2 ·
Replies
2
Views
1K
  • · Replies 10 ·
Replies
10
Views
771
  • · Replies 9 ·
Replies
9
Views
1K
  • · Replies 11 ·
Replies
11
Views
2K
  • · Replies 2 ·
Replies
2
Views
4K
  • · Replies 11 ·
Replies
11
Views
4K
  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 1 ·
Replies
1
Views
1K
  • · Replies 1 ·
Replies
1
Views
6K