2.1 System Mathematical Models
系统数学模型的建立
RC Low-Pass Circuit RC低通电路
A classic first-order LTI system. Adjust R and C to change the time constant, and observe how the system responds to different inputs.
经典一阶LTI系统。调节R和C改变时间常数，观察系统对不同输入的响应。
Input:
Parameters:
1.0
1.0
200
Equation:
Mass-Spring-Damper System 力学系统
A second-order LTI system. Adjust mass, damping, and spring constant to see underdamped, overdamped, or critically damped responses.
二阶LTI系统。调节质量、阻尼和弹簧刚度，观察欠阻尼、过阻尼或临界阻尼响应。
Input:
1.0
2.0
5
Equation:
Resource-Consumption: Cattle & Grass 资源-消耗系统：牛吃草
A first-order rate model. Grass grows at rate r per day; each cow eats c units per day.
How long until the pasture runs out?
一阶变化率建模。草每天以速率 r 生长，每头牛每天吃 c 单位。牧场什么时候吃光？
500
20
3.0
10
Equation: