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Homework Help: Calculating the pressure of a hailstone

  1. Jan 19, 2009 #1
    1. The problem statement, all variables and given/known data
    During a hailstorm , hailstones with an average mass of 2 g and a speed 15m/s strike a window pane at a 45 degree angle. The area of the window is .5 m^2 and the hailstones hit it at a rate of 30 per second. What average presure do they exert on the window? How does this compare to the pressure of the atmosphere?


    2. Relevant equations

    [tex]\overline{}[/tex]P=[tex]\overline{}[/tex]F/A=-m([tex]\Delta[/tex]vx/([tex]\Delta[/tex]t)/A


    3. The attempt at a solution

    N/s=30 hailstones/sec
    m=2 grams
    [tex]\Delta[/tex]vx=vx,final-vx,initial=(-vx-vx)=-2vx

    P=m(-2vx)/([tex]\Delta[/tex]t))*N/A=(2e-3 kg)(-2(15)(cos 45 degrees)(30))/(second)/(.5 m^2)

    to compare the pressure of the hail stone to the pressure of the atmosphere, wouldn't I take the ratio of the pressure of the hailstone to the pressure of the atmosphere?
     
  2. jcsd
  3. Jan 19, 2009 #2

    Dick

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    Science Advisor
    Homework Helper

    The pressure calculation looks ok to me. Sure, a ratio would be a good way to compare the two pressures.
     
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