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A question and no idea what to do

  • Thread starter ouse
  • Start date
  • #1
33
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determine the inital velocity of a projectile that is luncked horizantaly and falls 1.5m while moving 16m horizantaly
i tried everything all i figerd out is that they r displacmednts the accelaration is 9.8 and nothing i dont have enogh info to do anything
plz help me
 

Answers and Replies

  • #2
Päällikkö
Homework Helper
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Divide the motion into x and y components and deal with them as if you were dealing with one-dimensional motion.
 
  • #3
33
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can u plz elaborate
 
  • #4
33
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and any way that dosnt work becuse i have no angles to detrime wat the x and y componants are
 
  • #5
33
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that would only work if these were vectors not displacment
 
  • #6
Päällikkö
Homework Helper
515
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Well...
[tex]x = v_0t[/tex]
[tex]0 = y_0 -\frac{1}{2}gt^2[/tex]
Does that help at all?
 
  • #7
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yeah it helped i acctualy figerd the question thx sooo much
 
  • #8
33
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now can u plz look at my other thread and plz ohh plz help with question 1 b,c and q 2
 
  • #9
Päällikkö
Homework Helper
515
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ouse said:
yeah it helped i acctualy figerd the question thx sooo much
Glad to hear that :).

Did you understand where the equations I gave came from?
 
  • #10
33
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ummm well yeah for one of them
 
  • #11
33
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u assumed viy is 0 and took it our of the equation right
 
  • #12
Päällikkö
Homework Helper
515
10
The full equations:
[tex]x = x_0 + v_{x0}t + \frac{1}{2}a_xt^2[/tex]
[tex]y = y_0 + v_{y0}t + \frac{1}{2}a_yt^2[/tex]
Let [itex]x_0 = 0[/itex]. As the projectile's fired horizontally: [itex]v_{y0} = 0[/itex] thus [itex]v_{x0} = v_0[/itex]. No force affects the projectile in x-direction, so: [itex]a_x = 0[/itex]. In y-direction: [itex]a_y = -g[/itex] (- as it's downward). The final altitude of the projectile is [itex]y = 0[/itex].

Hence
[tex]x = v_0t[/tex]
[tex]0 = y_0 -\frac{1}{2}gt^2[/tex]
 
  • #13
33
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i was woundring if u could help me with the other thread plz help me i really need it i have a test i need to pass
 
  • #14
33
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thx for the explination
 

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