Problema Solution
A ball in thrown upward with an initial velocity of 96 ft/sec from a height of 640 feet. It's height h, in feet, after t seconds is given by h(t)= -16^2+96t+640. After how long will the ball reach the ground?
Answer provided by our tutors
the ground level is -640 feet, so we solve for a positive value of time, 't', from the provided equation for h(t)=-640
we do, however, correct the equation to "-16t^2 + 96t + 610" because if this correction is not made then the equation solves to t=-10.35
the formula you are providing is in error, please do not resubmit this problem or you will be blocked - if this formula is coming from your textbook then your textbook is in error
-640 = -16t^2 + 96t + 610
solving for 't' we have a positive value of t=12.3341
the ball will reach the ground in approximately 12.3 seconds