Homework # 1

1.8

This is a solution to this problem using Eulers method. It is an example that was gone over in class:

Matlab:

sigma = 300;

Q = 500;

A = 1200;

y=0;

time = [];

res = [];

delta_t=0.005;

for t = 0:delta_t:10,

time = [time,t];

res = [res,y];

y = y + delta_t*(3*Q/A*sin(t)^2-Q/A);

end

hold off;

plot(time,res);

hold on;

plot(time,(Q *(time-3* sin(time).* cos(time)))/(2* A),'r');

1.11

For this problem I just added up all the figures based on whether or not they were a positive or a negative value and got -1.2, which means to be stable you would need to drink at least 1.2 L of water per day.

1.16

1.18