ODE to answer projectile question

Hello,

I am a student and very weak with matlab, I come accross this question about projectiles for matlab and I am having a really bad time solving it. Would appreciate if somebody could help my deadline is in a few days!

The S number is defined like this RandStream.setGlobalStream(RandStream('mt19937ar','seed',1403767)); S=rand(1);

Answer 1

[Carlos Felipe Rengifo]

I hope this will help you:

clc;
clear variables;
close all;

% Parameters of the model
S       = rand(1);
M       = 10;
B       =  2;
g       =  9.81;
a       = deg2rad(35)*(1+0.2*S);
V0      = 28*(1+0.2*S);

% Dynamic model
% XDot = f(t,X), with X = [Vx,Vy,X,Y]
F       = @(t,X) [-B/M*X(1); -g-B/M*X(2); X(1); X(2)];

% Initial conditions
X0      = [V0*cos(a); V0*sin(a); 0; 0];

% Numerical solution
[T,X]   = ode45(F,[0,4],X0);

% Plots
subplot(2,2,1); plot(T,X(:,1)); title('Vx vs. Time'); grid on;
ylabel('Vel. [m/s]'); xlabel('Time [s]'); 
subplot(2,2,2); plot(T,X(:,2)); title('Vy vs. Time'); grid on;
ylabel('Vel. [m/s]'); xlabel('Time [s]'); 
subplot(2,2,3); plot(T,X(:,3)); title('X  vs. Time'); grid on;
ylabel('Pos. [m]'); xlabel('Time [s]'); 
subplot(2,2,4); plot(T,X(:,4)); title('Y  vs. Time'); grid on;
ylabel('Pos. [m]'); xlabel('Time [s]');

[James Tursa]

Please do not post complete solutions to homework problems.

[Carlos Felipe Rengifo]

I apologize for any inconvenience caused by my answer. I will be more careful next time.