Both sides previous revision Previous revision Next revision | Previous revision | ||
equations:newtons_second_law [2018/12/15 11:48] 93.132.16.208 boundary condition == initial condition in case variable is time |
equations:newtons_second_law [2018/12/15 12:01] (current) 93.132.16.208 Small change in the previous edit |
||
---|---|---|---|
Line 29: | Line 29: | ||
**Boundary or Initial Conditions** | **Boundary or Initial Conditions** | ||
- | Since Newton's second law contains the second derivative of the location: $\vec a = \frac{\partial^2 r}{\partial t^2}$, we need two boundary conditions to solve it. Since the independent variable here is time, //boundary// conditions are usually called //initial// conditions. (In technical terms, we say that Newton's law is a second order differential equation.) For example, we can use the location of the object at the starting time and the velocity at the starting time as boundary conditions. Alternatively, we could use, for example, the location of the object at two different points in time as boundary conditions. | + | Since Newton's second law contains the second derivative of the location: $\vec a = \frac{\partial^2 r}{\partial t^2}$, we need two boundary conditions to solve it. Whenever the independent variable is time, //boundary// conditions are usually called //initial// conditions. (In technical terms, we say that Newton's law is a second order differential equation.) For example, we can use the location of the object at the starting time and the velocity at the starting time as boundary conditions. Alternatively, we could use, for example, the location of the object at two different points in time as boundary conditions. |