calculating the velocity and distance of a rocket

A rocket gets up from the earth with speed 56.2917 and acceleration-9.81 .I need to solve the equation with ode45 command and get the velocity and distance in t=0:0.01:2.can you help me please

[James Tursa]

What have you done so far?

[Hossein]

this

[Torsten]

ds/dt = v,     s(0) = 0
dv/dt = -9.81, v(0) = 56.2917

Can you set up ode45 to solve these two ordinary differential equations ?

[Hossein]

I tried but it wasn’t useful.

[Torsten]

Sorry, but more help would be the solution.

Answer 1

[Image Analyst]

Why do you need differential equations? velocity = acceleration * time and distance = (1/2) a*t^2 + v*t + d0. You only are giving the downwards accelration due to gravity, not the acceleration due to the rocket thrust. And you are not giving the angle of the rocket but I guess you're assuming it's perfectly vertical.

Attached is a demo for a projectile with no drag with most parameters being variables that you can adjust the initial settings. It computes just about everything you can think of.

[Torsten]

Maybe better

distance = (1/2) a*t^2 + v0*t + d0

[Hossein]

It’s one of the project rules to be solved by ode45