Projectile Motion Lab: Finding Angle for Hitting a Falling Target

[jess2424]

I'm having some difficulty doing this lab, so if anyone could point me in the right direction that would be awesome.

I basically have to determine what angle to set a launcher at so that the projectile will hit a falling target. I have to derive an actual equation. The only measurements I will be able to make is the height of the target (before it falls) and the distance from the launcher to the target.

I've uploaded a crummy diagram of the set-up:


http://img323.imageshack.us/img323/1853/untitled5po.png


Remember, the only variable I'll be able to insert values for is 'h' and 'Dx'. I know that I have to start with the five kinematics equations, but I've reached a dead end.

Has anyone done this lab before? Is anyone able to point me in the right direction?

 

[ryanvergel]

Hmmm...

Since y=vy(t)-.5gt²
And since both the bullet and target need to meet at the same level, set the two y values equal to each other?

vsinθ-.5g(2vy/g)²=vsin0-5g((2y/g)^1/2)²
The first portion of the equality is the bullet, which follows a Case 2 motion, a parabolic path with an angle and non-zero vy component. The second portion of the equality is the case 1 scenario that the target follows.

try that out, it MIGHT help out. I don't know for sure of course, but it would be the first thing I would try-keep in mind I don't really know the problem, as in, what you need to show or do.

 

[hotvette]

https://www.physicsforums.com/showthread.php?t=91156