# Projectile Motion Problem -Diving off cliff

1. Oct 23, 2009

### Chandasouk

1. The problem statement, all variables and given/known data
A daring 510N swimmer dives off a cliff with a running horizontal leap, as shown in the figure .

I'm not sure how to begin, so I made a chart of the X and Y motions

X Motion Y Motion
--------- -----------------

VoX = ? Voy= 0m/s

/\X = 1.75m /\Y = 9.00m

a= -9.8m/s^2
t=?

I have no idea what to do with the 510N they give me or even if it is necessary

2. Oct 23, 2009

### Delphi51

I like your x and y motion chart - good start!
You will need to use some formulas to work out the initial velocity necessary to make it by the cliff. Ask yourself what kind of motion you have in the x direction and write down the appropriate equation(s). Same for the y direction.

Hot tip: you can make a perfect Δ here by copying one from https://www.physicsforums.com/blog.php?b=347 [Broken]
and pasting here.

Last edited by a moderator: May 4, 2017
3. Oct 23, 2009

### Chandasouk

Hmm, I think I found the time.

ΔY = 1/2at^2

9.00m = 1/2(9.8m/s^2)t^2

9.00m
------ = t^2
4.9m/s^2

t=1.35 seconds

Knowing this, I could

ΔX = voxt

1.75m = vox(1.35sec)

vox = 1.30m/s ?

4. Oct 23, 2009

### Redbelly98

Staff Emeritus
Looks good