document.write( "Question 1183278: I need help with this please. A baseball player throws a baseball from a height of 1 meter above the ground and its height is given by the equation 𝒉 = −𝟑. 𝟐𝒕^𝟐 + 𝟏𝟐.𝟖𝒕 + 𝟏, where 𝒉 is the height in metres above the ground, and t, in seconds, is its
\n" ); document.write( "time in the air [see the image below]. When, to the nearest tenth of a second, will the ball hit the ground? This is the image https://giannepaulaperalta.files.wordpress.com/2018/07/3075613-6448579381.jpg (you could pls copy and paste the link on a new tab). Also responding to the tutor that asked if I created this question on my own. To answer that no I didn't. This is a question from my assignments given to me by my teacher. \n" ); document.write( "

Algebra.Com's Answer #813509 by ikleyn(52787) $\"\"$ $\"About$

You can put this solution on YOUR website!
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\n" ); document.write( "\n" ); document.write( "The basic formula for the height as the function of time is written INCORRECTLY in your post.\r
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\n" ); document.write( "\n" ); document.write( "It has a FATAL ERROR, which makes the solution NONSENSICAL.\r
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\n" ); document.write( "\n" ); document.write( "To get the basic knowledge on the subject, read my post to the end.\r
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\n" ); document.write( "\n" ); document.write( "The problems on a projectile thrown-shot-launched vertically up are very popular.\r
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\n" ); document.write( "\n" ); document.write( "But, as I often observed, the students who meet such problems for the first time, often write
\n" ); document.write( "the basic equation incorrectly, because they do not understand the meaning of its terms.\r
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\n" ); document.write( "\n" ); document.write( "Therefore, I wrote this introductory lesson specially for beginners who don't know the subject AT ALL.\r
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document.write( "If you have the formula for a height given to you as a function of time in the form\r\n" );
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document.write( "    h(t) = -at^2 + bt + c,    (1)\r\n" );
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document.write( "where \"a\", \"b\" and \"c\" are real numbers, a > 0, then in this formula\r\n" );
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document.write( "    (a)  the initial height is equal to the coefficient \"c\" value;\r\n" );
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document.write( "    (b)  the initial velocity is the coefficient  \"b\" in the formula;\r\n" );
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document.write( "    (c)  the coefficient \"a\" value is half of the gravity acceleration.\r\n" );
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document.write( "         For the Earth conditions, the gravity acceleration is g = 9.81 m/s^2,\r\n" );
document.write( "         if you use meters for height.\r\n" );
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document.write( "         So, in this case, when you use meters as the measure of height,   a =  =  m/s^2  or 5 m/s^2  (approximate numerical value).\r\n" );
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document.write( "             +--------------------------------------------------------------+\r\n" );
document.write( "             |     It can not be 3.2 m/s^2, as it is written in your post.  |\r\n" );
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document.write( "    (d)  To find the height at the time moment \"t\", simply substitute the value of \"t\" into the formula (1) and calculate.\r\n" );
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document.write( "    (e)  To find the time \"t\" when the height has a given value h = , substitute  h =  into equation (1)\r\n" );
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document.write( "         and solve equation  \r\n" );
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document.write( "             h(t) = -at^2 + bt + c = .    (2)\r\n" );
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document.write( "    (f)  To find the time when the height is maximal, use the formula\r\n" );
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document.write( "              = .      (3)\r\n" );
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document.write( "    (g)  To find the maximal height, substitute the time value  t=   of the formula (3)  into the formula (1).\r\n" );
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\n" ); document.write( "\n" ); document.write( "To see numerous examples of solved problems, look into the lessons\r
\n" ); document.write( "\n" ); document.write( "    - Problem on a projectile moving vertically up and down\r
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\n" ); document.write( "\n" ); document.write( "    - OVERVIEW of lessons on a projectile thrown/shot/launched vertically up\r
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\n" ); document.write( "\n" ); document.write( "If this introduction is helpful to you, I will be happy.\r
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\n" ); document.write( "\n" ); document.write( "If it will be not enough to you to solve the problem, come again,\r
\n" ); document.write( "\n" ); document.write( "but with one indispensable condition: your equation MUST be written correctly.\r
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\n" ); document.write( "\n" ); document.write( "Regarding your teacher, you may show him (or her) this my post.   Or, if you hesitate do it, \r
\n" ); document.write( "\n" ); document.write( "give me his (or her) contact, and I will ask him (or her), why he (or she) gives wrong assignments.\r
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document.write( "    In the country where I growth and got my school and university education,\r\n" );
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document.write( "    it was UNTHINKABLE that a Math teacher gave an incorrect assignment.\r\n" );
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document.write( "    I can not recall even one single such case.\r\n" );
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document.write( "    It was not because the teachers were absolutely perfect -  they were normal people (very professional, although).\r\n" );
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document.write( "    But the educational system itself was so perfect that failed cases were impossible to happen inside of this system.\r\n" );
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