document.write( "Question 911969: A particle moves on a vertical line so that it's coordinate in feet at time (t) is s(t) = 4t^3 - 12t^2 +7 , t >= 0\r
\n" ); document.write( "\n" ); document.write( "a)
\n" ); document.write( "Find the Velocity function\r
\n" ); document.write( "\n" ); document.write( "b)
\n" ); document.write( "Find the Acceleration function\r
\n" ); document.write( "\n" ); document.write( "c)
\n" ); document.write( "When is the particle moving upward?\r
\n" ); document.write( "\n" ); document.write( "d)
\n" ); document.write( "When is the particle moving downward?\r
\n" ); document.write( "\n" ); document.write( "e)
\n" ); document.write( "What is the total distance that the particle travels in the time interval 0 <= t <= 3
\n" ); document.write( "
\n" ); document.write( "

Algebra.Com's Answer #553472 by jim_thompson5910(35256)\"\" \"About 
You can put this solution on YOUR website!
A particle moves on a vertical line so that it's coordinate in feet at time (t) is s(t) = 4t^3 - 12t^2 +7 , t >= 0\r
\n" ); document.write( "\n" ); document.write( "a)
\n" ); document.write( "Find the Velocity function\r
\n" ); document.write( "\n" ); document.write( "b)
\n" ); document.write( "Find the Acceleration function\r
\n" ); document.write( "\n" ); document.write( "c)
\n" ); document.write( "When is the particle moving upward?\r
\n" ); document.write( "\n" ); document.write( "d)
\n" ); document.write( "When is the particle moving downward?\r
\n" ); document.write( "\n" ); document.write( "e)
\n" ); document.write( "What is the total distance that the particle travels in the time interval 0 <= t <= 3
\n" ); document.write( "--------------------------------------------------------------------------------------------------------------------
\n" ); document.write( "--------------------------------------------------------------------------------------------------------------------
\n" ); document.write( "--------------------------------------------------------------------------------------------------------------------\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "a)
\n" ); document.write( "Find the Velocity function\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Differentiate the position function s(t) to get v(t) = s'(t) the velocity function\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "s(t) = 4t^3 - 12t^2 +7\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "s'(t) = 3*4t^2 - 2*12t^1 +0\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "s'(t) = 12t^2 - 24t\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "v(t) = 12t^2 - 24t\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "The velocity function is v(t) = 12t^2 - 24t\r
\n" ); document.write( "\n" ); document.write( "-------------------------------------------------------------------------\r
\n" ); document.write( "\n" ); document.write( "b)
\n" ); document.write( "Find the Acceleration function\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Differentiate the velocity function v(t) to get the acceleration function a(t) = v'(t). This is equivalent to finding the second derivative of s(t)\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "v(t) = 12t^2 - 24t\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "v'(t) = 2*12t^1 - 1*24t^0\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "v'(t) = 24t - 24*1\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "v'(t) = 24t - 24\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "a(t) = 24t - 24\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "The acceleration function is a(t) = 24t - 24\r
\n" ); document.write( "\n" ); document.write( "-------------------------------------------------------------------------\r
\n" ); document.write( "\n" ); document.write( "c)
\n" ); document.write( "When is the particle moving upward?\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "The particle moves upward when v(t) > 0, essentially when the velocity is positive.\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Graph v(t) = 12t^2 - 24t to get\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "We see that the velocity function is positive when \"t+%3C+0\" or \"t+%3E+2\". The inequality \"t+%3C+0\" does not make sense in this case because negative time is not possible. So only focus on \"t+%3E+2\"\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "The particle is moving upward when \"t+%3E+2\" (beyond 2 seconds)\r
\n" ); document.write( "\n" ); document.write( "-------------------------------------------------------------------------\r
\n" ); document.write( "\n" ); document.write( "d)
\n" ); document.write( "When is the particle moving downward?\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Use the same graph in part c) to find that the velocity is negative when \"0%3Ct%3C2\". This is when the particle is moving downward.\r
\n" ); document.write( "\n" ); document.write( "-------------------------------------------------------------------------\r
\n" ); document.write( "\n" ); document.write( "e)
\n" ); document.write( "What is the total distance that the particle travels in the time interval 0 <= t <= 3\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "D = total distance the particle travels in the time interval 0 <= t <= 3\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "The total distance traveled is 32 feet.
\n" ); document.write( "
\n" );