document.write( "Question 1034545: Please help me with this problem: An object is launched at 19.6 meters per second from a 58.8 meter tall platform. The equation for the object's height s at time t seconds after launch is s(t) = -4.9t2+ 19.6t + 58.8, where s is in meters.
\n" ); document.write( "a. When does the object strike the ground?
\n" ); document.write( "b. What was its maximum height?
\n" ); document.write( "c. How long will it take to reach its maximum height?
\n" ); document.write( " \n" ); document.write( "
Algebra.Com's Answer #649233 by addingup(3677)\"\" \"About 
You can put this solution on YOUR website!
You want to know when the object hits the ground so I'm looking for the time when the height s = 0
\n" ); document.write( "```````````````````````````````````````````````````````
\n" ); document.write( "The formula is:
\n" ); document.write( "s(t) = –gt^2+v_0t+h_0
\n" ); document.write( "The initial launch height was 58.8 meters, and the initial velocity (launch speed) was 19.6 m/s:
\n" ); document.write( "0 = –4.9t2+19.6t+58.8
\n" ); document.write( "0 = t2–4t–12
\n" ); document.write( "0 = (t–6)(t+2) split into 2 equations
\n" ); document.write( "t-6 = 0 or t+2 = 0
\n" ); document.write( "t = 6 or t = -2
\n" ); document.write( "We know the answer we are looking for is a positive number. Discard the -2:
\n" ); document.write( "The object strikes the ground in 6 seconds \n" ); document.write( "
\n" );