We consider an approximation of the gravity g=10.
Then the speed is given by the formula: s(t)=10t.
And the coordinate is given by the formula:x(t)=5t^2+t
(integrating the speed function).
Now set up the equation:

Solving the above equation for t we get:t =
14 seconds.
It will take 14 seconds for the penny to reach the ground.