183_notes:examples:deer_slug_example

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183_notes:examples:deer_slug_example [2014/09/26 04:28] pwirving183_notes:examples:deer_slug_example [2014/10/01 05:16] pwirving
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 === Lacking === === Lacking ===
 +
 +$\vec{F}_{net}$ on shoulder
  
 === Approximations & Assumptions === === Approximations & Assumptions ===
 +
 +${\Delta t} \longrightarrow  1/24s$ - Based on when a gun is fired in a movie, it usually occurs at about one movie frame, therefore, the collision time is less than 1/24s.
 +
 +$\vec{V}_{Slug} \longrightarrow 500m/s$ This is a conservative estimate based on an internet search.
 +
  
 === Representations === === Representations ===
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 Surroundings: Nothing Surroundings: Nothing
  
-$$\vec{F}_{net} = \dfrac{\Delta\vec{p}}{\Delta t}$$+{{183_notes:examples:momentum_example_2_upload.jpg?600|}} 
 + 
 +$\vec{F}_{net} = \dfrac{\Delta\vec{p}}{\Delta t}$ 
 + 
 +$\vec{p}_{sys,f} = \vec{p}_{sys,i}$ 
 + 
 +$\vec{p}_{1,f} + \vec{p}_{2,f} = \vec{p}_{1,i} + \vec{p}_{2,i}$ 
 + 
 +$m_1\vec{v}_{1,f} + m_2\vec{v}_{2,f} = m_1\vec{v}_{1,i} + m_2\vec{v}_{2,i}$
  
  
 === Solution === === Solution ===
 +
 +We know that the momentum of the system (gun + slug) does not change due to their being no external forces acting on the system, therefore, the change in momentum in the x-direction is 0.
 +
 +${\Delta p_x} = 0$
 +
 +In turn that means that the total change in momentum of the system is 0.
 +
 +$P_{tot,x} = 0$
 +
 +Because 
 +
 +$P_{tot,i,x} = 0$
 +
 +$0 = M_G * V_G + m_S * V_S \longrightarrow M_G * V_G$ is negative and $m_S * V_S$ is positive
 +
 +$V_G = {\dfrac{-m_s}{M_G}} V_S$
 +
 +$V_G = - {\dfrac{0.22kg}{3.5kg}}{500m/s} = -31.4m/s$
 +
 +Need to find what kind of force that is on your shoulder.
 +
 +$\vec{F}_{net} = \dfrac{\Delta\vec{p}}{\Delta t}$
 +
 +$\vec{F}_{net} =\dfrac{(3.5kg)(-31.4m/s + 0m/s)}{(1/24s)}$
 +
 +$\vec{F}_{net} = 2637.6N$ (at least)
 +
 +
 +
 +
  • 183_notes/examples/deer_slug_example.txt
  • Last modified: 2014/10/01 05:24
  • by pwirving