document.write( "Question 624215: The height h (in meters) of a cannonball t seconds after it is fired from a cannon is described by the equation h(t)=-49t^2+60t.\r
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Algebra.Com's Answer #392567 by ewatrrr(24785) $\"\"$ $\"About$

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document.write( "Hi,
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document.write( "The height h (in meters) of a cannonball t seconds after it is fired from a cannon is described by the equation
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document.write( " h(t)=-49t^2+60t.
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document.write( " a. What is the height of the cannonball after 4 seconds?   h(4) = -544m
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document.write( " b. How long will the cannonball be in the air? 1.22 sec
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document.write( "    0 = -49t^2 + 60t = t(-49t + 60)
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document.write( "    49t= 60
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document.write( "      t = 60/49 = 1.22 sec\r
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document.write( "Completing Square:  y = ax^2 + bx + c   ⇒ y = a(x -(-b/a2)^2 - a(-b/2a)^2 + c
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document.write( "   ,   V(60/98, 18.3673)
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document.write( "the vertex form of a Parabola opening up(a>0) or down(a<0), 
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document.write( " where(h,k) is the vertex and the Line of symmetry is x = h
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document.write( " c. How long does it take the cannonball to reach its maximum height? 60/98 sec
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document.write( " d. What is the maximum height of the cannonball? 18.3673m
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