document.write( "Question 298365: A rocket is scheduled to lift off from a stage 2ft. off the ground at an initial velocity of 80ft. per sec. How long is the rocket in the air? Use 32 ft/sec as the acceleration rate of gravity(G). What will be the maximum height of the rocket? The converted formula for the height of an object propelled unto the air is h=-16t squared +vt+h sub zero... I think I have height as being 2ft, velocity is 80ft per sec h sub zero is 2ft? I'm so confused! Help! Please! Thank you, Natalie \n" ); document.write( "
Algebra.Com's Answer #214654 by nerdybill(7384)![]() ![]() You can put this solution on YOUR website! A rocket is scheduled to lift off from a stage 2ft. off the ground at an initial velocity of 80ft. per sec. How long is the rocket in the air? Use 32 ft/sec as the acceleration rate of gravity(G). What will be the maximum height of the rocket? The converted formula for the height of an object propelled unto the air is h=-16t squared +vt+h sub zero \n" ); document.write( ". \n" ); document.write( "They give you the equation as: \n" ); document.write( "h(t) = -16t squared + vt + \"h sub zero\" \n" ); document.write( "where \n" ); document.write( "h(t) is height \n" ); document.write( "t is time \n" ); document.write( "v is velocity \n" ); document.write( "\"h sub zero\" is initial height \n" ); document.write( ". \n" ); document.write( "Given the data from the problem we now have: \n" ); document.write( "h(t) = -16t^2 + 80t + 2 \n" ); document.write( "This is a parabola. \n" ); document.write( "It opens downward (from the coefficient associated with the t^2 term). \n" ); document.write( "So, finding the axis of symmetry gives you the peak. \n" ); document.write( "\"axis of symmetry\" = -b/2a = -80/(2*(-16)) = -80/-32 = 2.5 \n" ); document.write( "So, when \n" ); document.write( "t = 2.5 seconds \n" ); document.write( "it will be at its peak. \n" ); document.write( ". \n" ); document.write( "To find the height, plug t back into: \n" ); document.write( "h(t) = -16t^2 + 80t + 2 \n" ); document.write( "h(2.5) = -16(2.5)^2 + 80(2.5) + 2 \n" ); document.write( "h(2.5) = 102 feet\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " |