Answer:
The distance of stars and the earth can be averagely measured by using the knowledge of geometry to estimate the stellar parallax angle(p).
From the equation below, the stars distances can be calculated.
D = 1/p
Distance = 1/(parallax angle)
Stellar parallax can be used to determine the distance of stars from an observer, on the surface of the earth due to the motion of the observer. It is the relative or apparent angular displacement of the star, due to the displacement of the observer.
Explanation:
Parallax is the observed apparent change in the position of an object resulting from a change in the position of the observer. Specifically, in the case of astronomy it refers to the apparent displacement of a nearby star as seen from an observer on Earth.
The parallax of an object can be used to approximate the distance to an object using the formula:
D = 1/p
Where p is the parallax angle observed using geometry and D is the actual distance measured in parsecs. A parsec is defined as the distance at which an object has a parallax of 1 arcsecond. This distance is approximately 3.26 light years
I think everything looks good but 2 might not be right, it might be B
La longitud <em>final</em> del puente de acero es 100.018 metros.
Asumamos que la dilatación <em>térmica</em> experimentada por el puente de acero es <em>pequeña</em>, de modo que podemos emplear la siguiente aproximación <em>lineal</em> para determinar la longitud <em>final</em> del puente de acero (
), en metros:
![L = L_{o}\cdot [1+\alpha\cdot (T_{f}-T_{o})]](https://tex.z-dn.net/?f=L%20%3D%20L_%7Bo%7D%5Ccdot%20%5B1%2B%5Calpha%5Ccdot%20%28T_%7Bf%7D-T_%7Bo%7D%29%5D)
(1)
Donde:
- Longitud inicial del puente, en metros. 
- Coeficiente de dilatación, sin unidad.
- Temperatura inicial, en grados Celsius.
- Temperatura final, en grados Celsius.
Si tenemos que 
, 
, 
y 
, entonces la longitud final del puente de acero es:
![L = (100\,m)\cdot [1+(11.5\times 10^{-6})\cdot (24\,^{\circ}C - 8\,^{\circ}C)]](https://tex.z-dn.net/?f=L%20%3D%20%28100%5C%2Cm%29%5Ccdot%20%5B1%2B%2811.5%5Ctimes%2010%5E%7B-6%7D%29%5Ccdot%20%2824%5C%2C%5E%7B%5Ccirc%7DC%20-%208%5C%2C%5E%7B%5Ccirc%7DC%29%5D)
La longitud <em>final</em> del puente de acero es 100.018 metros.
Para aprender más sobre dilatación térmica, invitamos cordialmente a ver esta pregunta verificada: brainly.com/question/24953416
•Every action has an equal and opposite reaction (the object is putting force on the target, and the target is putting an equal amount of force back)
•Am object in motion (the object) will stay in motion unless an outside force acts upon it (the Target)
And as for the third one I really don’t know, those seem to be the only two, I’m sorry. I did what a could, Hope it kinda helps :)
