Projectile Intercept Math & Trigonometry

AI Thread Summary
The discussion focuses on setting up equations for intercepting a projectile in a 3D scenario for a video game. The user seeks guidance on calculating the launch parameters needed to hit a target projectile launched at a specific angle and speed, with a delay in the interceptor's launch. Key advice includes equating the positions of both projectiles as functions of time to derive the necessary launch angles and speeds. It is emphasized that a general solution should be developed, allowing for variable parameters rather than fixed values. The conversation highlights the importance of abstract thinking in game design to accommodate changing conditions.
VexCarido
Messages
8
Reaction score
4
Looking for some guidance on how to set up the equations for a projectile intercept given that you have perfect information about the target velocity, size and weather conditions in a 3D scenario, it's for an amateur videogame that I'm developing in my spare time

For simplicity sake let's assume there's no wind force and that target object is launched from coordinate (5,100,0) at a 55 degree angle along the x-axis, with initial velocity of 40 m/s - we have to launch to intercept the projectile with a delay of 2 second after the initial object is launched. Time of Flight for the object is 6.68 seconds. and we're launching from the origin coordinate (0,0,0)

Our initial projectile launch velocity range is 60 to 120 m/s and with a solution we should end up with a list of possible combinations of angles, and projectile speeds that would successfully intercept the target.

I know how to calculate the trajectory, as well as the horizontal/vertical range & time of flight for both objects I don't think this should be more difficult than rearranging a few components of the equations of motion, but I am at a loss as to how I should go about it exactly. Is there a swift and easy & efficient way to do this?
 
Physics news on Phys.org
VexCarido said:
Is there a swift and easy & efficient way to do this?
I don't think there is. You are not answering a homework problem with specific input parameters. You need a general solution given the ever-changing parameters that depend on the user is doing. You are probably looking for expressions for the projection angles (##\theta,~\phi##) of the interceptor given that its speed is fixed at ##v_0.## So you need to write some equations for the position of the enemy projectile and the interceptor as functions of time, take the difference (note that the acceleration term drops out), and see what must be true for that difference to be zero.
 
kuruman said:
I don't think there is. You are not answering a homework problem with specific input parameters. You need a general solution given the ever-changing parameters that depend on the user is doing. You are probably looking for expressions for the projection angles (##\theta,~\phi##) of the interceptor given that its speed is fixed at ##v_0.## So you need to write some equations for the position of the enemy projectile and the interceptor as functions of time, take the difference (note that the acceleration term drops out), and see what must be true for that difference to be zero.
Figuring out the position of the target as a function of time is not the hard part, this can be done very simply by rearranging the 2D equation for the trajectory of a projectile to account for the added z axis.
d83a52c69a657e89c212ea32939f7c6a.png

Or by implementing the Euler method to approximate the trajectory instead.

It's what I do after this that I need help with. To simplify the problem even further let's fix our own initial launch velocity to 80 m/s.
 
VexCarido said:
Summary:: Need help to understand the math of projectile intercept for videogame

more difficult than rearranging a few components of the equations of motion, but I am at a loss as to how I should go about it exactly. Is there a swift and easy & efficient way to do this?
I think you will need to equate the coordinates of both the projectiles.
Equate the x(t) of 1st and second particle. And do the same with y(t). Put in the value of t.
You will get the angle of projection this way, using that you will get your other parameters.
A computer program would able to do this easily.
Sorry if I am wrong
 
Here is my question. Are you trying to shoot down projectiles that are aimed straight at you or are you trying to shoot down projectiles that are aimed at your headquarters located away from you on a hillside? And no, let's not get too attached to 80 m/s. Lets's call our projectile speed ##v_0## and the speed of the enemy projectile ##u_0##. Develop the equations and then you can tweak the values as you wish. I think that if you wish to be a successful game designer, you have to think abstractly in terms of parameters.
 
The rope is tied into the person (the load of 200 pounds) and the rope goes up from the person to a fixed pulley and back down to his hands. He hauls the rope to suspend himself in the air. What is the mechanical advantage of the system? The person will indeed only have to lift half of his body weight (roughly 100 pounds) because he now lessened the load by that same amount. This APPEARS to be a 2:1 because he can hold himself with half the force, but my question is: is that mechanical...
Some physics textbook writer told me that Newton's first law applies only on bodies that feel no interactions at all. He said that if a body is on rest or moves in constant velocity, there is no external force acting on it. But I have heard another form of the law that says the net force acting on a body must be zero. This means there is interactions involved after all. So which one is correct?
Thread 'Beam on an inclined plane'
Hello! I have a question regarding a beam on an inclined plane. I was considering a beam resting on two supports attached to an inclined plane. I was almost sure that the lower support must be more loaded. My imagination about this problem is shown in the picture below. Here is how I wrote the condition of equilibrium forces: $$ \begin{cases} F_{g\parallel}=F_{t1}+F_{t2}, \\ F_{g\perp}=F_{r1}+F_{r2} \end{cases}. $$ On the other hand...
Back
Top