SOLUTION: Using The Quadratic Formula, how could you determine the amount of time it would take for a diver to touch water after leaping off the platform. Here's an example equation th

Algebra ->  Quadratic Equations and Parabolas  -> Quadratic Equation Customizable Word Problems -> SOLUTION: Using The Quadratic Formula, how could you determine the amount of time it would take for a diver to touch water after leaping off the platform. Here's an example equation th      Log On


   

Question 1032105: Using The Quadratic Formula, how could you determine the amount of time it would take for a diver to touch water after leaping off the platform.
Here's an example equation
the height +h+ of a diver in meters above the pool after +t+ seconds can be approximated by the equation
+h+=+4.9f%5E2+%2B+3f+%2B+10+
Found 2 solutions by josmiceli, ikleyn:
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
+h+=+-4.9t%5E2+%2B+3t+%2B+10+
When the diver hits the water,
+h+=+0+ ( zero height above water )
+-4.9t%5E2+%2B+3t+%2B+10+=+0+
Use the quadratic formula
+t+=+%28-b+%2B-+sqrt%28+b%5E2-4%2Aa%2Ac+%29%29%2F%282%2Aa%29+
+a+=+-4.9+
+b+=+3+
+c+=+10+
+t+=+%28+-3+%2B-+sqrt%28+3%5E2-4%2A%28-4.9%29%2A10+%29%29%2F%282%2A%28-4.9%29%29+
+t+=+%28+-3+%2B-+sqrt%28+9+%2B+196+%29%29%2F%28-9.8%29+
+t+=+%28+-3+%2B-+sqrt%28+205+%29%29%2F%28-9.8%29+
+t+=+%28+-3+-+14.3178+%29+%2F+%28+-9.8+%29+
+t+=+%28+-17.3178+%29+%2F+%28+-9.8+%29+
+t+=+1.767+
The diver hits the water in 1.767 sec
check:
+-4.9t%5E2+%2B+3t+%2B+10+=+0+
+-4.9%2A1.767%5E2+%2B+3%2A1.767+%2B+10+=+0+
+-4.9%2A3.122+%2B+5.271+%2B+10+=+0+
+-15.298+%2B+15.271+=+0+
+-.027+=+0+
Error may be due to rounding off
check my math

Answer by ikleyn(52748) About Me  (Show Source):
You can put this solution on YOUR website!
.
Using The Quadratic Formula, how could you determine the amount of time it would take for a diver to touch water after leaping off the platform.
Here's an example equation
the height +h+ of a diver in meters above the pool after +t+ seconds can be approximated by the equation
+h+=+4.9f%5E2+%2B+3f+%2B+10+
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~`

Hello,

did you noticed that you incorrectly presented your equation?

It should be

+h+=+-4.9t%5E2+%2B+3t+%2B+10+.     (sign  "-"  before the first term and  "t"  instead of  "f")

The other tutor did everything correct and used just corrected equation.