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Slav-nsk [51]
2 years ago
6

Một vật được ném lên trên theo phương thẳng đứng. Người quan sát

Physics
1 answer:
Arte-miy333 [17]2 years ago
4 0

Answer:

Language -English plz I cant understand

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An astronomical unit (A.U.) is 1 point A) a term for defining the luminosity of a star B) the average distance from the Earth to
Elenna [48]

Answer:

B) the average distance from the Earth to the Sun

Explanation:

7 0
2 years ago
16. The energy absorbed in 10minutes by an electrical heater is 1.5 MJ. The supply voltage is 240 V. calculate: a) The current d
dsp73

Answer:

If by 1.5 MJ you mean 1.5E6 Joules then

W = P t    = power X time

W / t = P   power

P = 1.5E6 J / 600 sec = 2500 J / s

P = I V

a) I = 2500 J/s / (240 J/c) = 10.4 C / sec  = 10.4 amps

b) Q = I t = 10.4 C / sec * 300 sec = 3120 Coulombs

c)  E = P * t = 2500 J / sec * 100 hr * 3600 sec / hr = 9.0E8 Joules

5 0
2 years ago
Two polarizing sheets have their transmission axes crossed so that no light is transmitted. A third sheet is inserted so that it
jek_recluse [69]

Answer:

a)    I= I₀ (cos²θ - cos⁴θ)    b) 75.5º

Explanation:

a) For this exercise we must use Malus's law

         I = I₀ cos² θ

where tea is the angle between the two polarizers.

We apply this expression to our case

* Polarizer 1 suppose that it is vertical and polarizer 2 (intermediate) is at an angle θ with respect to the vertical

         I₁ = I₀ cos² θ

* We analyze for the polarity 2 and the last polarizer 3 which indicate that it must be at 90º from the first one, therefore it must be horizontal.

The angle of polarizers 2 and 3 is θ' measured from the horizontal, if we measure with respect to the vertical

              θ₂ = 90- θ’ = θ

fiate that in the exercise we must take a reference system and measure everything with respect to this system.

          I = I₁ cos² θ'

       

we substitute

         I = (I₀ cos² tea) cos² (θ - 90)

        cos (θ -90) = cos θ cos 90 + sin θ sin 90 = sin θ

         I = Io cos² θ sin² θ

        1= cos²θ+ sin²θ

       sin²θ = 1 - cos²θ

        I= I₀ (cos²θ - cos⁴θ)

b) to find when the intensity is maximum,

we can use that we have an extreme point when the drift is zero

          \frac{dI}{d \theta} = 0

          \frac{dI}{d \theta}= Io (2 cos θ - 4 cos³θ) = 0

whereby

            cos θ - 2 cos³ θ = 0

            cos θ ( 1 - 2 cos² θ) = 0  

The zeros of this function are in

           θ = 90º

           1-2cos²θ =0       cos θ = 0.25  θ =  75.5º

Let's analyze this two results for the angle of 90º the intnesidd is zero with respect to the first polarizer, so it is not an acceptable solution.

Consequently, the angle that allows the maximum intensity to pass is 75.5º

5 0
2 years ago
The respiratory system - 2/3
stepan [7]

The answers to the respiratory questions are listed below:

  • 6). Trachea
  • 7).  Pneumonia
  • 8). True
  • 9).  False
  • 10). Hair

<h3>Meaning of a respiratory system</h3>

A respiratory system is a biological system found in both plants and animals, which includes organs and structures used for exchanging gas between the organisms and its environments.

A respiratory system is a network or chain or organs and tissues that enables breathing.

In conclusion, the respiratory system is one that is very important to understand.

Learn more about respiratory system : brainly.com/question/1270124

#SPJ1

3 0
2 years ago
Name the types of forces​
Lostsunrise [7]
Air resistance force
tension force
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frictional force
normal force
gravitational force
applied force

please give me brainly:)
6 0
3 years ago
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