<u>Answer</u>
5.the stage before a star becomes a main sequence star
<u>Explanation</u>
A protostar is a small star that is still gathering its masses. When it forms enough masses it make a parent molecular cloud.
This been the case, from the choices given, the correct statement about a protostar is;
5.the stage before a star becomes a main sequence star
To solve this problem we will apply the concepts related to the calculation of the speed of sound, the calculation of the Mach number and finally the calculation of the temperature at the front stagnation point. We will calculate the speed in international units as well as the temperature. With these values we will calculate the speed of the sound and the number of Mach. Finally we will calculate the temperature at the front stagnation point.
The altitude is,
And the velocity can be written as,
From the properties of standard atmosphere at altitude z = 20km temperature is
Velocity of sound at this altitude is
Then the Mach number
So front stagnation temperature
Therefore the temperature at its front stagnation point is 689.87K
Answer:
The highest vertical position is where your maximum potential energy lies. At the highest altitude point of course ! This is when the kinetic energy is only due to horizontal motion (since the vertical component reaches zero).
Explanation:
i looked it up ok
Answer:
D. Airplane wings must be designed to ensure that air molecules move more rapidly over the top surface of the wing, creating a region of lower pressure.
Explanation:
Bernoulli's theory operates on the assumption that its shape makes the air travel more over the top of the wing than under it as a plane moves through the air. Due to the pressure difference, wings feel a lifting force and create lift force. when pressure decrease than the velocity of the fluid will increase.
Therefore the answer is D.
