Our atmosphere is attracted by earths what?
1 answer:
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Answer:
Star X is much closer since it is at a distance 1 parsec from the Earth.
Explanation:
The angle due to the change in position of a nearby object against the background stars it is known as parallax.
The parallax angle can be used to find out the distance by means of triangulation. Making a triangle between the nearby star, the Sun and the Earth. This angle is gotten when the position of the object is measured in January and then in July according to the configuration of the Earth with respect to the Sun in those months.
The distance between the Earth and the Sun is 150000000 Km. That distance is also known as an astronomical unit (1AU).
The parallax angle can be defined in the following way:
Where d is the distance to the star.
(1)
Equation (1) can be rewritten in terms of d:
(2)
Equation (2) represents the distance in a unit known as parsec (pc).
Case of Star X (p('') = 1):
Using equation 2 the distance of star X can be known:
So, star X is at 1 parsec from Earth.
Case of Star Y ():
So, star Y is at 2 parsecs from the Earth.
Hence, star X is much closer.
Reminder:
Notice that in equation 2 the distance is inversely proportional to the parallax angle, so if the parallax angle decreases, the distance increases.
Answer:
From lowest to highest acceleration:
3rd train
2nd train
1st train
Explanation:
The acceleration of an object can be found by using Newton's second law:
where
a is the acceleration
F is the net force on the object
m is the mass of the object
We notice that for equal values of the forces F, the acceleration a is inversely proportional to the mass, m. Therefore, greater mass means lower acceleration, and viceversa.
So, the train with lowest acceleration is the one with largest mass, i.e. the 3rd train consisting of 50 equally loaded freight cars. Then, the 2nd train has larger acceleration, since it consists of 50 empty freight cars (so its mass is smaller). Finally, the 1st train (a single empty car) is the one with largest acceleration, since it is the train with smallest mass.
