# Projectile help

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rajesh msen    125
Hi to all, I tried to do cannon projectiles for a game.I know the destination point where the cannon should land and also have a option of selecting the speed it travels say from 80 Kph to 100 Kph.I need to know the angle.How can i find the angle (theta) for the projectile .MY Launching position is higher than the landing position.Please help me fix this.Thanks in Advance ---Rajesh---

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swiftcoder    18437
If you want the simulation to be physically correct, then the wikipedia article on trajectory contains all the necessary formulas. If you have a basic background in physics or calculus, that should be enough to go on.

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rajesh msen    125
I tried it but i don't know how to solve the equation with unknown variable theta.Any help guys

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Fenrisulvur    186
How much wind resistance? Zero? Some?

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rajesh msen    125
I need the angle of elevation.I know the launch point its greater than the target,I know the destination point where it should land,i know the speed it travels(its option for users to select the speed between (60 - 100),I need the angle of elevation to reach the destination point.
Ex : Angle of elevation differs based on the value of the variable speed.

---Rajesh---

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jpmcmu    184
Is the starting elevation the same as the ending elevation?

Assuming that you don't care about air resistance or the rotation of the earth you can use the range equation. I probably wont get it right of the top of my head so I am not going to try, a quick google search should find it.

If you want air resistance or need differing final and initial elevations, I can derive the equations for you and email them to you.

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swiftcoder    18437
Quote:
 Original post by rajesh mseni know the speed it travels(its option for users to select the speed between (60 - 100)
If you want movement to be physically correct, then speed of the projectile is not a constant. Generally you would want the user to adjust the initial speed instead.

It is also the case that if the initial speed is insufficient, you won't be able to reach the target, no matter what launch angle you pick.

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rajesh msen    125
I am sure the mechanism is already already used in lot of games.Example: Cricket games where the user choose where the ball should pitch.Any Help