document.write( "Question 1087358: An astronaut on Mars throws a ball into the air with an initial velocity of 30 feet per second from a platform 36 feet tall. Gravity on Mars is approximately -12 feet per second per second (-12). So, the height h of the ball t seconds after it is thrown is given by h6t2 30t 36. (a) How high is the ball after 3 seconds? \n" ); document.write( "

Algebra.Com's Answer #701653 by jorel1380(3719) $\"\"$ $\"About$

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If the gravity on Mars is equal to -12 ft./s², then the formula for a projectile, launched from a platform 36 ft. high, with a velocity of 30 ft./sec., would be:
\n" ); document.write( "h(t)=-12/2 t²+30t+36
\n" ); document.write( "After 3 seconds, you have:
\n" ); document.write( "h(3)=-6(9)+90+36=72 ft.
\n" ); document.write( "The ball will return to Mars at:
\n" ); document.write( "0=-6t²+30t+36
\n" ); document.write( "6t²-30t-36=0
\n" ); document.write( "t²-5t-6=0
\n" ); document.write( "(t-6)(t+1)=0
\n" ); document.write( "t=6 seconds before the ball hits the Martian surface.
\n" ); document.write( "☺☺☺☺ \n" ); document.write( "

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