# I believe I can Fly~I believe I can touch the sky

1. Dec 5, 2011

### maxtheminawes

1. The problem statement, all variables and given/known data
Augustine continues to run around. He gets to the park and has the overwhelming urge to jump off a cliff and try to fly. He does so at an angle of 50 degrees to the horizontal while running at 14.5m/s. With his arms flapping, he rises in the air.
a) what is the highest point from the top of the cliff that he reaches before the laws of physics catch up with him and start bringing him back down to Earth?
b)What is his velocity at that point?
c)If the cliff is 10m high, how long is he in the air before he comes crashing down to the nice, soft, sandy beach below the cliff?
d)what is his final velocity?
e)what is his final horizontal displacement from the cliff?

2. Relevant equations
v=vo+at
y=yo+vot+1/2at^2
x=xo+vot+1/2at^2
v=final velocity
vo=initial velocity
yo=initial y displacement
xo=inital x displacement

3. The attempt at a solution
a) Vx=14.5cos50=9.32
Voy=14.5sin50= 11.11

v=vo+at
0=(9.32)+(-9.8)t
-9.32=-9.8t
-.95=t
.95sec=t

y=yo+vot+1/2at^2
y=11.11(.95)+1/2(-9.8)
y=1.23m

b)1.8m/s

c).95secs

d)v=vo+at
v=14.5+(-9.8)(.95)
v=5.59m/s

e)x=xo+vot+1/2at^2
x=14.5(.95)+1/2(-9.8)(.95^2)
x=23.85m
1. The problem statement, all variables and given/known data

2. Relevant equations

3. The attempt at a solution

2. Dec 6, 2011

### ehild

Distinguish between horizontal and vertical components of acceleration, velocity and displacement.
What is horizontal component of acceleration?

ehild

3. Dec 6, 2011

### maxtheminawes

i really have no clue. is it constant. i know that acc downwards is -9.8m/s^2

4. Dec 6, 2011

### HallsofIvy

Staff Emeritus
Yes, and (ignoring friction) that constant is 0! There is no horizontal force and so no horizontal component of acceleration.