index Expo Renew Nonrenew 2source Slowren Factors Recycle Daypr

## Growth on a Nonrenewable Source

#### Description:

A nonrenewable source is a storage, a limited quantity. A population living of a nonrenewable source first increases exponentially while their source decreases. As soon as the source is used up, the population decreases too.

#### Examples:

• A mining town living on a limited source of gold ore
• A person given an inheritance: He uses the money for going on trips. As the money runs out, his trips decrease and then cease.
• #### Variables:

E = nonrenewable energy source
K = decreasing factor of E
K1 = increasing factor of Q
K4 = decreasing factor of Q

#### Equations:

DE = -K*E*Q
DQ = K1*E*Q-K4*Q

#### Simulation:

The graph shows the changes of E (blue) and Q (red) over a time period.
Source code: Nonrenew.java

#### "What if" Experiments:

Think about a population of beetle that grow of a limited quantity of dead wood:

• What would happen if the tree which fell in the storm was a bigger one?
• What would happen if you started with 100 times more beetles?
• Try a different species of beetles which have a more efficient growth rate.