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
garri49 [273]
2 years ago
7

Please Help!

Physics
1 answer:
e-lub [12.9K]2 years ago
3 0

Answer:

Q9. Man who received the most altercations for a theory which later on became a revolutionary theory influenced in many areas of modern science and technology.

Q10. Fire truck is coming towards you

Explanation:

Q9. Christian  Doppler was born on 29th of November 1803 in Saltzburg. After studies in Linz and Vienna, he graduated in Mathematics. For many years, Doppler struggled to find work in academia, and for a time he worked as a bookkeeper at a factory. His academic career took him from Austria to Prague, where he became assistant at the University and later worked as professor in Prague. Back to Vienna, he was appointed as professor at the Polytechnic School and in 1850 as first director of the new Institute of Physics. While working at Vienna, his health broke down and moved Venice where he sought his eternal rest on March 17th, 1953.

During his lifetime, the man was quite controversial: a personality praised by some, but detested by others; and even as a scientist, he had a difficult time. He did publish papers on magnetism, electricity, optics and astronomy but, the discovery that allowed him to remain in history of science was the one he presented at Royal Bohemian Society of Science entitled "On the colored light of the double stars and certain other stars of the heavens" in 1842. He hypothesized that the pitch of the sound would change if the source was moving.

Doppler's ideas were initially received with a certain amount of skepticism so, in order to support his claims, he devised an experiment in 1845 with the help of colleague. He used two sets of trumpeters, one set stationary at a train station and  one set moving on an open train car. Both sets of musicians had perfect pitch and held the same note. As the train passed the station, it was obvious that the frequency of the two notes didn't match, even though the musicians were playing same note. This proved his hypothesis.

Demonstrating that the Doppler effect also held true for frequency of ligh proved more difficult and was never successfully achieved before Doppler's demise. The first experiment that revealed a Doppler shift in starlight was carried out at the beginning of twentieth century. Since then Doppler effect was proved invaluable for astronomical observations.

For the most of the academic world, he is known as physicist; but one can equally find him on the list of mathematicians and astronomers too. This is proof for the exceptional broad spectrum of application of his main discovery.

Q10. When there is increase in frequency of the sound from source, then the source is moving towards you. Hence the fire truck is coming towards you

You might be interested in
What is the push and pull of a man about to hit a golf ball with a golf club. Is it causing a change in SPEED, or DIRECTION, or
ivanzaharov [21]
It would be both speed and direction depending on the man's swing 
5 0
3 years ago
PLEASE HELPPPPPPPP<br> What is the average velocity of a train that goes 86 km in 1.3 hours?
olga_2 [115]
The answer is:

V = d/t d = 86 km t = 1.3 hrs

V = 86 km/ 1.3 hrs

V = 66.15 km/ hrs

I hope this helps!!
5 0
2 years ago
A rocket ship is accelerating at 200 m/s2, its mas is 135,000,000 kg. What is the force generated by this acceleration?
Rina8888 [55]

Acceleration does NOT "generate" force.  Acceleration NEEDS force to make it happen.  Without force ... provided by something else ... acceleration can't happen.

The force NEEDED to accelerate a mass with a certain acceleration is

Force needed = (mass) times (acceleration)

For the rocket ship in the question,

Force = (135,000,000 kg) times (200 m/s²)

Force = (135,000,000 x 200) kg-m/s²

<em>Force = 27 Giga-Newtons  </em>(27,000,000,000 Newtons)


The gas-generator cycle F-1 rocket engine, developed in the US by Rocketdyne in the late 1950s, was used in the Saturn V rocket, the main launch vehicle of NASA's Apollo moon lander program .  Five F-1 engines were used in the first stage of each Saturn V.  

==> The thrust of each F-1 engine at full throttle is 7,770 kilo-Newtons.  

It would take <em>3,475 </em>of these F-1 rocket engines, running full-throttle, to provide the force calculated in the answer to this question.  If you didn't have 3,475 F-1 rocket engines, then you couldn't accelerate 135,000,000 kg at 200 m/s².

(And by the way ... the mass of each F-1 engine is 8,400 kg.  So 3,475 engines alone account for 22% of the mass you're trying to accelerate.  And don't even get me started about the mass of the FUEL you'd need to carry.)

5 0
3 years ago
Which method will correctly determine whether the forces on an object are balanced or unbalanced?
MaRussiya [10]

For this case, the first thing you should do is define a reference system.

Once the system is defined, we must follow the following steps:

1) Do the sum of forces in a horizontal direction

2) Do the sum of forces in vertical direction

The forces will be balanced if for each direction the net force is equal to zero.

The forces will be unbalanced if for each direction the net force is nonzero.

Answer:

Add the forces in the horizontal and vertical directions separately.

6 0
3 years ago
Read 2 more answers
PLEASE HELP ASAP:
antoniya [11.8K]

True since coulomb's law states that There is electric force between like charges or opposite charges. The negative sign only shows the nature of the force.

<h3>What is the coulombs law ?</h3>

coulombs formula is given by

F=  \dfrac{K\times q_{1} \times q_{2}}{r^{2} }

Now it states that if two charged particles are separated by the distance r and having same or opposite charge will attract or repel each other.

The intensity of the force depend upon the distance and the nature of the charge.

Hence coulomb's law states that There is electric force between like charges or opposite charges. The negative sign only shows the nature of the force.

To know more about coulomb's law follow

https://brainly.in/question/332179

8 0
2 years ago
Read 2 more answers
Other questions:
  • A cylinder has a length of 3.23 cm, a diameter of 1.75 cm, and a mass of 65.3 grams. What is the density of the cylinder? Based
    12·1 answer
  • Two charges, -20 C and +4.7 C, are fixed in place and separated by 3.0 m. a. At what spot along a line through the charges is th
    6·1 answer
  • BRAINLIEST FOR THE FIRST TO ANSWER
    7·1 answer
  • Two masses, A and B, are attached to different springs. Mass A vibrates with an amplitude of 8 cm at a frequency of 10 Hz and ma
    12·1 answer
  • What is the ecliptic, and why is it tilted with respect to the celestial equator?
    15·1 answer
  • A nation undergoing the transition from undeveloped to industrialized is commonly dependent on this to supply its energy needs.
    14·2 answers
  • Which occurrence would contradict the big bang theory?
    11·2 answers
  • A 750 kg car moving at 25 m/s has Kinetic Energy. To stop the car requires work. On snowy roads, the force of friction that can
    11·1 answer
  • Which of the best describes a solution
    10·1 answer
  • Find the kenetic energy of a car of mass 700kg racing with a velocity of 10m/s
    13·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!