document.write( "Question 971729: A metal ball (with a mass of 5.0 kg) is dropped from a building 320 meters tall.
\n" ); document.write( "How many seconds does it take to hit the ground?
\n" ); document.write( "What is the ball's velocity just before impact?\r
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\n" ); document.write( "\n" ); document.write( "Madison \n" ); document.write( "
Algebra.Com's Answer #594121 by Alan3354(69443)\"\" \"About 
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A metal ball (with a mass of 5.0 kg) is dropped from a building 320 meters tall.
\n" ); document.write( "How many seconds does it take to hit the ground?
\n" ); document.write( "What is the ball's velocity just before impact?
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\n" ); document.write( "The commonly used value for acceleration due to Earth's gravity is 9.8 m/sec/sec
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\n" ); document.write( "Neglecting air friction:
\n" ); document.write( "--> h(t) = -4.9t^2 + 0t + 320 where t = seconds and h(t) = height AGL
\n" ); document.write( "At impact, h(t) = 0
\n" ); document.write( "h(t) = -4.9t^2 + 0t + 320 = 0
\n" ); document.write( "t^2 = 320/4.9
\n" ); document.write( "t =~ 8.081 seconds
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\n" ); document.write( "v = at = 9.8*8.081
\n" ); document.write( "=~ 79.196 m/sec
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\n" ); document.write( "The mass is not a factor.
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