## 2nd Order Ordinary Differential Equation

### JoonHee Joh (view profile)

on 17 Dec 2015
Latest activity Edited by JoonHee Joh

### JoonHee Joh (view profile)

on 21 Dec 2015
How do you solve the following 2nd order ODE
so this question describes the motion of an object in 3-D space
r vector represents the position of an object a vector is an acceleration vector caused by drag g vector simply represents the gravitational acceleration where g_z = -9.8
r(0) is given by
and r'(0) or v(0) is given by
* Now here is my question *
Assuming that drag is 0 (thus, a vector simply reduces to 0) and given initial conditions above
How can you find the time(t_I) at which the object hits the ground (r = 0)
and how can you express the position and velocity of this object as functions of time?
Can anyone provide the MATLAB code to solve these problems?? :P

### Torsten (view profile)

on 18 Dec 2015

If the drag is zero, the general solution is
x(t) = x(0) + vx(0)*t + gx/2*t^2
y(t) = y(0) + vy(0)*t + gy/2*t^2
z(t) = z(0) + vz(0)*t + gz/2*t^2
Best wishes
Torsten.