Answer: Within any frame of reference that is accelerating
Special relativity was proposed on 1905 by Einstein, who developed his theory based on the following two postulates:
1. <em>The laws of physics are the same in all inertial systems. There is no preferential system.
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2. <em>The speed of light in vacuum has the same value for all inertial systems.
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Focusing on the first postulate, it can be affirmed that <u>any measurement on a body is made with reference to the system in which it is being measured</u>.
Now, taking into account that an inertial reference system is the one that complies with the principle of inertia:
<em>"For a body to have acceleration, an external force must act on it."</em>
The correct answer is
Within any frame of reference that is accelerating
An electric current flows when electrons move through a conductor, such as a metal wire. The moving electrons can collide with the ions in the metal. This makes it more difficult for the current to flow, and causes resistance.
Answer:
A)
2. very cool but very luminous
6. found in the upper right of the H-R diagram
B)
1. The majority of stars in our galaxy
5. the Sun, for example
7. a very hot and very luminous star
C)
3. not much larger in radius than Earth
4. very hot but very dim
Explanation:
Main-sequence stars :
Main-sequence stars are the star which having hydrogen in the core and also having stable inward and outward force.
White dwarfs :
This is also a star like the sun .The temperature of these type of star above 100,000 Kelvin.The mass of White dwarfs is less than the sun but slightly more than earth.
Red giant or supergiant stars :
This is the biggest star in the universe.When a star does not having hydrogen fuel in the core then Red giant or supergiant stars are formed.
A) 2 ,6
B) 1 , 5 ,7
C) 3 ,4
Answer:
his is a multi-part question. Once an answer is submitted, you will be unable to return to this part. Air enters a nozzle steadily at 2.21 kg/m3 and 40 m/s and leaves at 0.762 kg/m3 and 192 m/s. The inlet area of the nozzle is 90 cm2.
determine (a) the mass flow rate through the nozzle, and (b) the exit area of the nozzle.
a)0.7956kg/s
b)5.437 × 10⁻³m²
Explanation:
The concepts related to the change of mass flow for both entry and exit is applied
The general formula is defined by
Where,
values are divided by inlet(1) and outlet(2) by
PART A) Applying the flow equation
PART B) For the exit area we need to arrange the equation in function of Area, that is