1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
-BARSIC- [3]
2 years ago
6

Doppler effect is caused by sound or light wave being pushed together and spread apart due to motion. True or False.

Physics
1 answer:
pychu [463]2 years ago
3 0

Answer: false.

Explanation:

Doppler effect is caused to the relative motion of the source of light/sound with respect to the observer.

If the source is moving towards you, you will perceive the frequency to be larger (also called a blue shift), while if the wave is moving away, you will perceive the frequency to be smaller (also called a red shift).

Then the statement:

"Doppler effect is caused by sound or light wave being pushed together and spread apart due to motion."

Is false

You might be interested in
Steam in a heating system flows through tubes whose outer diameter is 5 cm and whose walls are maintained at a temperature of 13
svet-max [94.6K]

Answer:

5945.27 W per meter of tube length.

Explanation:

Let's assume that:

  • Steady operations exist;
  • The heat transfer coefficient (h) is uniform over the entire fin surfaces;
  • Thermal conductivity (k) is constant;
  • Heat transfer by radiation is negligible.

First, let's calculate the heat transfer (Q) that occurs when there's no fin in the tubes. The heat will be transferred by convection, so let's use Newton's law of cooling:

Q = A*h*(Tb - T∞)

A is the area of the section of the tube,

A = π*D*L, where D is the diameter (5 cm = 0.05 m), and L is the length. The question wants the heat by length, thus, L= 1m.

A = π*0.05*1 = 0.1571 m²

Q = 0.1571*40*(130 - 25)

Q = 659.73 W

Now, when the fin is added, the heat will be transferred by the fin by convection, and between the fin and the tube by convection, thus:

Qfin = nf*Afin*h*(Tb - T∞)

Afin = 2π*(r2² - r1²) + 2π*r2*t

r2 is the outer radius of the fin (3 cm = 0.03 m), r1 is the radius difference of the fin and the tube ( 0.03 - 0.025 = 0.005 m), and t is the thickness ( 0.001 m).

Afin = 0.006 m²

Qfin = 0.97*0.006*40*(130 - 25)

Qfin = 24.44 W

The heat transferred at the space between the fin and the tube will be:

Qspace = Aspace*h*(Tb - T∞)

Aspace = π*D*S, where D is the tube diameter and S is the space between then,

Aspace = π*0.05*0.003 = 0.0005

Qspace = 0.0005*40*(130 - 25) = 1.98 W

The total heat is the sum of them multiplied by the total number of fins,

Qtotal = 250*(24.44 + 1.98) = 6605 W

So, the increase in heat is 6605 - 659.73 = 5945.27 W per meter of tube length.

5 0
3 years ago
3. Which planet, other than Earth, is confirmed to have water on it?
Nadusha1986 [10]
Mars.

Water exists as small amounts of ice on Mars and as water vapor. It is suspected that Mars used to have flowing water on it, but that there is none left now.
8 0
2 years ago
What is it that lives if it is fed, and dies if you give it a drink?
Anna71 [15]

Fire is it that lives if it is fed, and dies if you give it a drink.

<h3><u>Explanation:</u></h3>

Fire is very essential part of human life. It is used for cooking food and for other important activities. Without fire we cannot not survive. Something or the other should be heated before consumption and this can be achieved only with fir. It is also used in the darker places for viewing many things around us.

Thus, fire can survive if we give fuel or any wooden pieces and when water is poured on it it will turn off. Hence Fire is the one that survives when it is fed and dies when water is given as a drink to it.

4 0
3 years ago
The core of the Sun has a temperature of 1.5 × 107 K, while the surface of the Sun has a temperature of 4870 K (which varies ove
ololo11 [35]

Answer:

The Sun and planets are shown to the same scale. The small terrestrial planets and tiny Pluto are in the box---the Earth is the blue dot near the center of the box (montage created by Nick Strobel using NASA images).

Size

The Sun is by far the biggest thing in the solar system. From its angular size of about 0.5° and its distance of almost 150 million kilometers, its diameter is determined to be 1,392,000 kilometers. This is equal to 109 Earth diameters and almost 10 times the size of the largest planet, Jupiter. All of the planets orbit the Sun because of its enormous gravity. It has about 333,000 times the Earth's mass and is over 1,000 times as massive as Jupiter. It has so much mass that it is able to produce its own light. This feature is what distinguishes stars from planets.

Composition

What is the Sun made of? Spectroscopy shows that hydrogen makes up about 94% of the solar material, helium makes up about 6% of the Sun, and all the other elements make up just 0.13% (with oxygen, carbon, and nitrogen the three most abundant ``metals''---they make up 0.11%). In astronomy, any atom heavier than helium is called a ``metal'' atom. The Sun also has traces of neon, sodium, magnesium, aluminum, silicon, phosphorus, sulfur, potassium, and iron. The percentages quoted here are by the relative number of atoms. If you use the percentage by mass, you find that hydrogen makes up 78.5% of the Sun's mass, helium 19.7%, oxygen 0.86%, carbon 0.4%, iron 0.14%, and the other elements are 0.54%.

Explanation:

4 0
3 years ago
The pattern of weather in an area overtime is called
zzz [600]
The pattern of the temperature in a region day by day is called weather. The year by year temperature is a called climate.
6 0
3 years ago
Other questions:
  • Is the following sentence true or false? Two atoms of the same element can have different numbers of protons.
    14·1 answer
  • Why don’t metals break when hit with hammer
    9·1 answer
  • An electron and a proton are held on an x axis, with the electron at x = + 1.000 m and the proton at x = - 1.000 m. Part A How m
    8·1 answer
  • In principle, when you fire a rifle, the recoil should push you backward. How big a push will it give? Let's find out by doing a
    6·1 answer
  • What is needed to cause a change in the state of matter? a. Adding or removing energy c. Changing the arrangement of atoms b. Ch
    6·2 answers
  • 5. The boiling point of mercury is lower than<br> that of alcohol.
    8·2 answers
  • How does the theory of relativity explain the gravity exerted by massive objects?
    5·1 answer
  • Which statement about oceans is incorrect?
    9·1 answer
  • Which city did King David make the royal capital of the Kingdom of Israel?
    7·1 answer
  • A train travels 190km in 3.0 hours and then 120 km in 2.0 hours. What is it’s average speed ?
    7·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!