Hi , I need help please)

1). 50 liter vessel contains air (80 % nitrogen and 20 % oxygen). In 0.1 liter vessel flows in a second nitrogen which is continuously stirred , and flows the same amount of the mixture. How long in the vessel will be 90 % of the nitrogen ? Graphically nitrogen filled vessel with respect to time

2). Consider the problem of simultaneous motion of a particle with constant mass in a gravitational field of the Earth . Build a relationship coordinates of a material point on the time dependence of the velocity of the coordinate dependence of the traversed path of the material point of time.

[Roger Stafford]

Please show us what progress you have made on the problem so far. This looks as if it is a homework assignment in English, translated, not too successfully, from a different language.

Here is a hint. Problem 1) will lead to a differential equation involving the amount of nitrogen in the big vessel in terms of the volume flowing in against the volume flowing out. Matlab has functions that handle differential equations. Problem 2) will also lead to differential equations of a somewhat more complicated form.

[Image Analyst]

http://www.mathworks.com/matlabcentral/answers/8626-how-do-i-get-help-on-homework-questions-on-matlab-answers