# Homework Help: Question with solution, confused on how time was found.

1. Jul 7, 2017

### I'm Awesome

1. The problem statement, all variables and given/known data
A skier (m=59.0 kg) starts sliding down from the top of a ski jump with negligible friction and takes off horizontally. If h = 6.60 m and D = 10.6 m, find H.

2. Relevant equations

3. The attempt at a solution

The solution was provided, this is a sample problem. I'm just very confused in how t was found to be sqrt(2h/g)

http://imgur.com/a/UuRNp

2. Jul 7, 2017

### NFuller

I assume you are referring to the fourth line where time was substituted out using the equation
$$t=\sqrt{\frac{2h}{g}}$$.
This is simply the time taken for an object to fall a vertical distance $h$ and comes from re-arranging the one-dimensional motion equation
$$x=\frac{1}{2}at^{2}$$
and using $h$ for vertical distance and $g$ for acceleration.

3. Jul 7, 2017

### haruspex

How are D, h and H defined in the question? The link to the solution works, but it looks like there is also a broken link, perhaps to the original question, or a diagram of it?