Projectile Motion Help - Find Angle of Elevation for Rajesh

[rajesh.msen]

Hi to all,
I have a problem in projectile motion.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.I not good in maths and very new to physics.Any one help me to solve this problem.Even tell me if the solution is not exit.
Help me guys.Thanks in advance.


---Rajesh---

Homework Statement

velocity,launch_point,landing_point

Homework Equations

The Attempt at a Solution

 

[tiny-tim]

Welcome to PF!

Hi Rajesh! Welcome to PF!

Write equations for the x and y components separately.

For x, remember that the x component of velocity is constant.

For y, use the standard constant acceleration equations.

 

[rajesh.msen]

Hi tiny thanks to reply,
Actually i confused a lot because people recommends me some link http://hyperphysics.phy-astr.gsu.edu/Hbase/traj.html
http://books.google.co.za/books?id=...resnum=9&ved=0CBoQ6AEwCA#v=onepage&q=&f=false

I followed it but i am not good in solving equations.Can you suggest which one is better to solve my equation.Thanks in advance

 

[tiny-tim]

Hi Rajesh!

(btw, no need to PM me … everyone gets automatic email notification of any reply to a thread that they've contributed to )

The question gives you v_i (but not its direction), and x and y.

So call the time t, and call the direction θ, so that the initial components of velocity are v_icosθ horizontally and v_isinθ vertically.

Then use the standard constant acceleration equations for the horizontal direction (a = 0) and the vertical direction (a = -g) separately: that gives you two equations, from which you can eliminate t, so you get one equation for θ.