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3 years ago

PLZZZ HELP FAST AND RIGHT THANK YOU

Physics

2 answers:

dezoksy [38]3 years ago

4 0

Explanation:

An open system is defined as a system in which there occurs exchange of both matter and energy as well.

For example, a cup full of hot tea is an open system which can exchange matter and energy with its surroundings.

On the other hand, a closed system is defined as a system which can exchange energy with its surrounding but it cannot exchange matter.

For example, a cup of hot tea closed with a lid is a closed system which can exchange energy with its surrounding.

Therefore, we can conclude that the statement in an open system matter freely moves and energy can enter or leave the system.

Pepsi [2]3 years ago

4 0

The answer would be C. because in a open system matter and energy can move around in the air. The only obvious answer is C plus I just took the test

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Radio waves travelling at 3x108 m/s have a frequency of 1.017x108 Hz. Its wavelength is m rounded to the nearest tenth.

jonny [76]

Answer: 3 metres

Explanation:

The wavelength of a wave is the distance covered by the wave after one complete cycle. It is measured in metres, and represented by the symbol λ.

Recall that Velocity (V) = Frequency F x wavelength λ

In this case, wavelength (λ)= ?

Frequency of radio wave = 1.017x10^8 Hz

Velocity of radio waves = 3x10^8 m/s

Apply V = F λ

3x10^8 m/s = 1.017x10^8 Hz x λ

Make λ the subject formula

λ = (3x10^8 m/s / 1.017x10^8 Hz)

λ = 2.95 metres (To the nearest tenth, it becomes 3 metres)

Thus, the wavelength of the radio waves is 3metres

8 0

4 years ago

In a fluorescent tube of diameter 3 cm, 3 1018 electrons and 0.75 1018 positive ions (with a charge of e) flow through a cross-s

Vinil7 [7]

Answer:

The current in the tube is 0.601 A

Explanation:

Given;

diameter of the fluorescent, d = 3 cm

negative charge flowing in the fluorescent tube, -e = 3 x 10¹⁸ electrons/second

positive charge flowing in the fluorescent tube, +e = 0.75 x 10¹⁸ electrons/ second

The current in the fluorescent tube is due to presence of positive and negative charges to create neutrality in the conductor (fluorescent tube).

Q = It

I = Q/t

where;

I is current in Ampere (A)

Q is charge in Coulombs (C)

t is time is seconds (s)

1 e = 1.602 x 10⁻¹⁹ C

3 x 10¹⁸ e/ s = ?

= (3 x 10¹⁸ e/s x 1.602 x 10⁻¹⁹ C) / 1e

= 0.4806 C/s

negative charge per second (Q/t) = 0.4806 C/s

positive charge per second (Q/t) = (0.75 x 10¹⁸ e/s x 1.602 x 10⁻¹⁹ C) / 1e

positive charge per second (Q/t) = 0.12015 C/s

Total charge per second in the tube, Q / t = (0.4806 C/s + 0.12015 C/s)

I = 0.601 A

Therefore, the current in the tube is 0.601 A

7 0

3 years ago

Who could explain the phenomenom of interference of light?

Likurg_2 [28]

Answer:

When the waves reflected from the inner and outer surface combine they will interfere with each other, removing or reinforcing some parts of white light by destructive or constructive interference. ... This results in color.

Explanation:

this is what we studied

so basically there is like a surface

and 2 different waves coming out of the same source

they will combine and start removing parts of the white light (which originally consists of 6 to 7 colors)

results in showing these colors

6 0

3 years ago

Although 0 dB is often referred to as the lower threshold of human hearing, it is important to realize that the human ear is not

IRISSAK [1]

Answer:

20 Hz

15.8 times

Explanation:

Although the range of frequency for any human's ear is usually said to be between 20 Hz and 20 kHz. And since the question asked for the least intense frequency, that has to be 20 Hz. Essentially the frequency most people perceive the least intense sound is 20 Hz.

A 100-Hz sound must be 10^1.2 times or 15.8 times more intense compared to a 1000-Hz sound to be perceived as equal to 60 phons of loudness

5 0

3 years ago

I was reading an old thermodynamics textbook and came across this equation describing change in internal energy. What does the (

RoseWind [281]

Explanation:

I remember that notation! The expression

$dQ = dU = (\dfrac{\partial U}{\partial T})_{V} dT+ (\dfrac{\partial U}{\partial V})_{T}dV$

is the 1st law of thermodynamics and it refers to the heat supplied to the system dQ which is also a change in its internal energy dU. The first term is the <u>partial</u> derivative of the internal energy U with respect to temperature T while the volume V is kept constant, as denoted by the subscript V. The 2nd term is similar but this time, temperature is kept constant while its volume partial derivative is being taken.

Ah, memories!

8 0

3 years ago