### Conservation Laws Fundamental Forces Estimation Of Distances

**Conservation Laws:**

**Law of Conservation of Mass:**- Matter cannot be created or destroyed during a reaction, but can change form.

**Law of Conservation of Energy:**- The total amount of energy in an isolated system remains the same.

**Law of Conservation of Momentum:**- The total momentum of an isolated system remains constant.

**Law of Conservation of Angular Momentum:**- The total angular momentum of an isolated system remains the same.

**Fundamental Forces:**

**Gravitational Force:**- An attractive force between any two objects with mass.

**Electromagnetic Force:**- A force acting between charged particles, stronger between oppositely charged particles.

**Strong Nuclear Force:**- A force binding the subatomic particles (quark) in atomic nuclei.

**Weak Nuclear Force:**- A force behind the radioactive decay of some subatomic particles.

**Estimation of Distances:**

**Parallax Method:**- Determining the distance to a star by observing its position from different points.

**Triangulation Method:**- Using angles from two known positions to calculate the distance to an object.

**Radar Method:**- Measuring the time taken for a radar pulse to bounce back from an object.

**Echo Method:**- Measuring the time it takes for a sound echo to return, thus estimating distance to objects from sound waves.

**Spectroscopic Method:**- Measuring the spectrum of stars to approximate the distance based on its redshift or blueshift.