Which of these objects would show the greatest parallax?a. the Sun
b. Mars
c. the Moon
d. Polaris
What is the distance an object would be from Earth if its parallax were one arcsecond?
a. a parsec
b. a light-year
c. an arcminute
d. an angular diameter

Answer:

C. yellow

Explanation:

The stars have different color depending on their temperature, in general the more blue or violet a star is, the higher its surface temperature, and the more orange or red, the lower its surface temperature.

In the stellar classification, stars with temperatures ranging from 5000K to 6000K are G type stars which are characterized by having a yellow color.

An example of a G-type star is the sun, which has a surface temperature of around 5700K.

Answer:

Explanation:

T=2π√l/g

to solve this for l we have to remove the square root in order to finish square root we have to take square on both side so the equation become

T²=4π²l/g

multiplying g on both side

T²g=4π²l

now dividing 4π² on both side

T²g/4π²=l

so l=T²g/4π²

Right answer: The weight of the air displaced is less than the volume of the balloon

A hot air balloon is a cloth wrap that contains several thousand cubic meters of air inside (a large volume of air). The burner (which is the motor of the balloon and responsible for its elevation) heats the liquid propane to a gaseous state to generate a huge flame, thus heating the air mass inside the balloon. In this way, its density is modified with respect to the air that surrounds it, because the hot air is lighter than the outside air (less dense), causing the balloon to rise and float.

Now, if we know that the density of a body is directly proportional to its mass and inversely proportional to its volume:

We can deduce that

by increasing the volume of the body, its density will decrease.

This is proof of Archimedes' Principle:  

A body totally or partially immersed in a fluid at rest, experiences a vertical upward thrust equal to the mass weight of the body volume that is displaced.

In this case the fluid is the air outside. So, the warm air inside the balloon, being less dense, will weigh less than the outside air and therefore will receive an upward pushing force or thrust that will make the balloon ascend.