Question

Tranh dives off a 9 m platform. He reaches a maximum height of 9.2 m after 0.26 s. How long does it take him to reach the water to the nearest hundreth of a second?

Answer 1

He will reach the ground after 2.023 seconds.

To start, write a quadratic equation in vertex form with the given information about the vertex.

$y=a(x-2.6)^2+9.2$

All that we need to solve for is a. Plug in the point (0, 9) and you will be able to solve for a and write the complete equation.

Now, just use the quadratic formula and you will get 2.023 seconds for when he hits the ground.