Question

What are two types the momentum?

Answer 1

1. Momentum is the product of a particle's mass and velocity at a given instance.
2. Newton's second law states that the force is equal to the rate of change of momentum. For a constant mass, force is equal to the product of mass and acceleration.
3. Principle of conservation of linear momentum: If the net external force acting on a system of bodies is zero, then the momentum of the system remains constant.
4. According to Newton's second law
   $$\begin{gathered} \mathrm{Force}=\frac{\mathrm{change}\mathrm{in}\mathrm{momentum}}{\mathrm{time}} \\ \overrightarrow{F}=\frac{d\overrightarrow{p}}{\mathrm{dt}} \end{gathered}$$
5. Thus, if $\overrightarrow{F}=0$, then the momentum can be constant or zero.
6. Principle of conservation of angular momentum: Angular momentum of a system is conserved as long as there is no net external torque acting on the system
   $\mathrm{Angular}\mathrm{momentum}=\mathrm{radius}\mathrm{of}\mathrm{the}\mathrm{circularpath}\times \mathrm{linear}\mathrm{momentum}$
   $\overrightarrow{\mathrm{L}}=\overrightarrow{\mathrm{r}}\times \overrightarrow{\mathrm{p}}$
7. The rate of change of angular momentum is equal to the torque of the rotational motion.
   $$\begin{gathered} \mathrm{Torque}=\frac{\mathrm{change}\mathrm{in}\mathrm{angular}\mathrm{momentum}}{\mathrm{time}} \\ \tau =\frac{\mathrm{dL}}{\mathrm{dt}} \end{gathered}$$