# Projectile Motion Problem!

1. Sep 14, 2010

1. I got the first part right but I cannot figure out how to do the second part!! Help please! And thank you!

Volcanoes on the Earth eject rocks at speeds of up to 170 m/s. Consider a 1750 m high volcano which ejects rocks in all directions. What is the maximum height above sea level reached by rocks?

part B: Consider a rock ejected an angle of 30degrees. How far from the axis of the volcano (horizontally) will it strike the ocean?

2. Sep 14, 2010

### scustin

separate your x and y components

x:
v0x=170cos30
x=?
t= from y

y:
v0y =170sin30
a =-9.81m/s^2
y = -1750m
t =
solve for t using y=v0*t+(1/2)at^2
then plug t into your x component to get x

(make sure to keep your initial y velocity positive and your acceleration and y distance negative)

3. Sep 10, 2012

### omc1

Hi, Iam currently working on a similar problem and I keep getting it wrong. I found t to equal 17.34s or 3.57s by using the quadratic formula i then took a time and plugged it back into the formula using all the x component numbers and got 2429.14m or 4084.41m both are wrong.

my volcano is 2000m high and rocks are shooting at 45 degree angle traveling at 170m/s.
thanks