SOLUTION: A body moves in a straight line with an acceleration of 10 m/s^2. If after 2 s it passes through O and after 3 s it is 25 m from O, find its initial position relative to O. I ju

Algebra ->  Customizable Word Problem Solvers  -> Travel -> SOLUTION: A body moves in a straight line with an acceleration of 10 m/s^2. If after 2 s it passes through O and after 3 s it is 25 m from O, find its initial position relative to O. I ju      Log On

Ad: Over 600 Algebra Word Problems at edhelper.com


    

Question 1046774: A body moves in a straight line with an acceleration of 10 m/s^2. If after 2 s it passes through O and after 3 s it is 25 m from O, find its initial position relative to O.
I just cannot form an equation to find the integral.. please help!
Answer by robertb(5830) About Me  (Show Source):
You can put this solution on YOUR website!
a+=+d%5E2x%2Fdt%5E2+=+10
===> dx%2Fdt+=+10t%2Bc ===> x+=+10%2A%28t%5E2%2F2%29+%2Bct%2Bd+=+5t%5E2+%2Bct+%2Bd
x(2) = 0 ===> 5%2A2%5E2+%2B2c+%2Bd+=+0 ===> 2c+d = -20.
x(3) = 25 ===> 5%2A3%5E2+%2B3c+%2Bd+=+25 ===> 3c+d = -20.
Solving simultaneously,
c = 0 and d = -20.
===> x%28t%29+=5t%5E2+-+20 ===> x(0) = -20, or, at the start, the body is 20 meters to the left of O.