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
Anastaziya [24]
2 years ago
9

Have you heard an ambulance, police car, or fire truck recently? Did you notice that the pitch of the siren changed as it approa

ched you and then again as it moved away? What concept explains this change or shift in sound waves?
Physics
2 answers:
Tanzania [10]2 years ago
5 0
The Doppler Effect is the change in frequency or wavelength of a wave for an observer moving relative to its source. It is named after the Austrian physicist Christian Doppler.
Bumek [7]2 years ago
3 0

Answer: Doppler effect

Explanation:

When there is relative motion between source and listener of sound, the apparent frequency heard by the listener is different from the frequency of the source. When the source and the listener are moving closer, the apparent frequency increases and when they move apart, there is decrease in the apparent frequency. This is Doppler's effect.

The wave-fronts move closer as the source and listener approach closer to each other. Thus, the observed frequency is greater than the actual. The pitch depends on frequency, greater is the pitch.

You might be interested in
What pushes against gravity in: a main sequence star, a white dwarf, a neutron star, and a black hole? electron degeneracy, neut
Inga [223]

Answer:

heat pressure, electron degeneracy, neutron degeneracy, and nothing

Explanation:

Main Sequence Star: It is a star in which nuclear fusion is happening in the core of the star. Hydrogen molecules fuse together to generate Helium. This nuclear fusion generates outward gas pressure and radiation pressure which balances the inward gravity thus creating an equilibrium which keeps the stars in shape.

White dwarf: It is the end stage of a medium sized star like the Sun. Outer layers of the star are thrown in the form a shell/bubble leaving a small and dense core in the center called as white dwarf. This core consists of carbon and oxygen. Nuclear fusion doesn't occur in the core of white dwarfs. The inward gravity is balanced by the electron degeneracy pressure. Thus these stars will keep on radiating the remaining heat and will turn in to a black dwarf at the end.

Neutron Star: This is the end stage of a supermassive star (1-3 times the mass of the Sun). At the last stage of the life the core collapses. In these stars the inward gravity is so huge that the pressure overcomes the electron degeneracy pressure and crushes together the electron and proton to form neutron. The neutron then stops the collapse and balances the inward gravity.

Black Hole: This is the end stage of a hyper massive stars weighing more than 3 times the mass of the Sun. The inward gravitational force is so huge that even the neutrons are not able to stop the collapse the core. thus the mass of the star collapses into a very small area of immense gravity. There is nothing that can balance this inward gravity.

3 0
2 years ago
A short-wave radio antenna is supported by two guy wires, 155 ft and 175 ft long. Each wire is attached to the top of the antenn
Vladimir79 [104]

Answer:

163.8 ft

Explanation:

In triangle ABD

AB = 155 ft

Cos63 = \frac{BD}{AB} = \frac{BD}{155}\\BD = 155 Cos63 \\BD = 70.4 ft

Sin63 = \frac{AD}{AB} = \frac{AD}{155} \\AD = 166 Sin63\\AD = 148 ft

Using Pythagorean theorem in triangle ADC

AC^{2} = AD^{2} + DC^{2} \\175^{2} = 148^{2} + DC^{2} \\DC = 93.4 ft

d = distance between the anchor points

distance between the anchor points is given as

d = BD + CD = 70.4 + 93.4\\d = 163.8 ft

5 0
3 years ago
Read 2 more answers
Onur drops a basketball from a height of 10m on Mars, where the acceleration due to gravity has magnitude of 3.7 m/s^2. We want
denpristay [2]

Answer:

2.32 s

Explanation:

Using the equation of motion,

s = ut+g't²/2............................ Equation 1

Where s = distance, u = initial velocity, g' = acceleration due to gravity of  the moon, t = time.

Note: Since Onur drops the basket ball from a height, u = 0 m/s

Then,

s = g't²/2

make t the subject of the equation,

t = √(2s/g')...................... Equation 2

Given: s = 10 m, g' = 3.7 m/s²

Substitute this value into equation 2

t = √(2×10/3.7)

t = √(20/3.7)

t = √(5.405)

t = 2.32 s.

4 0
3 years ago
Read 2 more answers
If Sherry took her pulse for 6 seconds and felt 14 beats, What would her heart rate be?
Tom [10]

Answer:

140 beats per minute

Explanation:

You have to multiply the ratio 14 beats/6 seconds by 10 because 6 seconds times 10 to get 1 minute. The answer you get is 140 beats/60 seconds.

3 0
2 years ago
How much force does an 88kg astronaut exert on his chair while accelerating straight up at 10 m/s^2
Fed [463]
Force=mass*acceleration.         So 88kg*10 m/s^2=880 newtons
6 0
3 years ago
Other questions:
  • Yosef is playing with different kinds of rubber bands. Some are very narrow and some are quite wide. Yosef is curious about the
    13·2 answers
  • What is the effect of friction on a moving object
    14·1 answer
  • What characteristic of waves is defined as the number of waves that pass a given point per unit time?
    5·1 answer
  • Determine the total moment of inertia of a merry-go round with 5 children sitting on it. Of the five children, four are seated a
    6·1 answer
  • An optical disk drive in your computer can spin a disk up to 10,000 rpm (about 1045 rad/s). If a particular disk is spun at 646.
    6·1 answer
  • A rock is dropped from the ceiling of a truck's cargo bay. with the truck moving at constant velocity, the rock strikes the floo
    5·1 answer
  • An ideal air-filled parallel-plate capacitor has round plates and carries a fixed amount of equal but opposite charge on its pla
    15·1 answer
  • Determine whether the interference is constructive or destructive at each location indicated.
    15·1 answer
  • An object with a mass of 2.0 kg accelerates 2.0 m/s when an unknown force ls applied to it. Wha is the amount of force?
    6·1 answer
  • Part 1- An ideal gas, initially at a volume of 1.71429 L and pressure of 7 kPa, undergoes isothermal expansion until its volume
    15·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!