A police siren has a frequency of 340.0 Hz when the car is stationary and the temperature is 20°C. The police car at point S moves to the right with a speed of 22.0 m/s.
a. What frequency does observer A hear?
b. What frequency does observer B hear?
c. Suppose observer A is moving toward the stationary police car. What is the speed of observer A if the frequency heard is 369 Hz?
Answer:
a) 361.7 Hz
b) 318.1 Hz
c) 29.3 m/s
Explanation:
a) Speed of sound in 20 degrees celcius is 343 m/s.
Use v=wavelength*frequency to find wavelength.
343=wavelength*340
wavelegth=1.009 meters
Relative speed of waves to observer A = 343+22 = 365 m/s
Plug it back in.
365=1.009*F
F=361.7 Hz
b) Relative speed of waves to observer B = 343-22 = 321 m/s
Plug it back in.
321=1.009*F
F=318.1 Hz
c) STATIONARY CAR, so 369Hz=v/1.009. v=372.3, 372.3-343=29.3m/s!
Please help me with these calculating velocity questions im so stressed out
Answer: -10m/s
Explanation:
Velocity is solved using the equation displacement over time. Part C shows a displacement or change in x of 30 and a change in time of 3 secs (7-10) so the equation would be 30m/3s= -10m/s it is negative because look at the slope. Its decreasing right? So that means the objects is slowing down which means it can't have a positive velocity
A 2-inch, f/4 reflector has a focal length of:
6 inches
8 inches
4 inches
2 inches
Your student desk has been in the room for many hours, it is at thermal equilibrium with the room?
Which part of your desk is colder: the wood or the metal? Why?
Answer:
metal because A: In general, metals feel colder or hotter to the touch than other materials at the same temperature because they're good thermal conductors. This means they easily transfer heat to colder objects or absorb heat from warmer objects. Thermal insulators like plastic and wood don't transfer heat as easily.
Explanation:
The Atoms Family
Sub-atomic Particle Charge
Location in the atom Mass of particle
Proton
Neutron
Electron
Please help this is really confusing
One of the signs a chemical reaction is taking place
Answer: One of the signs a chemical reaction is taking place is the presence of bubbles. :)
What kind of surface causes regular reflection? Expalin.
Explanation The regular reflection takes place when the light rays are incident on a polished smooth surface like a plane mirror, a stainless steel sheet and a thin sheet of aluminum, so, the reflected rays of light move only in a fixed direction.
A car weighs 11000 N on Earth. What is its mass?
A) 300 kg
B) 1122 kg
C) 0 kg
D) 107,800 kg
The first mineral to melt from a rock is
Answer:
Quartz
Explanation:
Answer:
Quartz
Explanation:
The temperature must be high enough to melt at least some minerals in the rock. The first mineral to melt from a rock will be quartz
Sometimes an electric bulb does not glow even if it is connected to the cell. What could be the reason
Answer:
Probable Reason - Break in filament of electric bulb
Explanation:
An electric bulb might not glow even if it is connected to the cell, possibly because of break in the filament of electric bulb. As, break in bulb's filament implies break in flow of electric current - between electric cells' terminal.
An evident example of this is , a fuse bulb doesn't light up as the current doesn't pass through filament.
Hank's mother got tired of everyone's cell phones ringing during dinner, so she wrapped all
of the cell phones in aluminum foil at dinnertime. Which of the following best explains how
Hank's mother solved her problem?
Cell phone signals are electromagnetic waves, which are absorbed by the aluminum foil
Cell phone signals are electromagnetic waves, which are reflected by the aluminum foil
Cell phone signals are mechanical waves, which are absorbed by the aluminum foil
O Cell phone signals are mechanical waves, which are reflected by the aluminum foil
Answer:
Cell phone signals are electromagnetic waves, which are reflected by the aluminum foil
Answer:
I think the best answer would be the first but am I the only one wondering why the mom didn't just turn off the phone but instead she had to be extra and wrap them up like a gift to give them after dinner.
Read the description of the centrioles. What is their function?
Answer:
Typically found in eukaryotic cells, centrioles are cylindrical (tube-like) structures/organelles composed of microtubules. In the cell, centrioles aid in cell division by facilitating the separation of chromosomes. For this reason, they are located near the nucleus.
Answer:
sorry im just gettig points but the actaul anserw is on top of this oneExplanation:
Bye
The moon revolves around Earth. The moon travels at a speed of about 1 km/s. What keeps the moon in orbit around Earth?
A.Nuclear Fusion
B.Gravity
C.Magnetism
D.Ocean Tides
Answer:
I know its not A or D so its B or C and the more logical answer would be B. gravity
Explanation:
A researcher releases a weather balloon to study the atmosphere. The air temperature on the ground is 27 degrees. If the sensors read an air temperature of 17 degrees, then how far up has the balloon traveled?
Answer:- Input for computer-based weather prediction models;
- Local severe storm, aviation, fire weather, and marine forecasts;
- Weather and climate change research;
- Input for air pollution models;
- Ground truth for satellite data
Explanation:
From an apple tree 2 metres high, a 100g mass apple fell of the tree, what work did it do?
Answer:
When an apple falls from the tree to the ground, its energy of position (stored as gravitational potential energy) is converted to kinetic energy, the energy of motion, as it falls. When the apple hits the ground, kinetic energy is transformed into heat energy.
As a person pushes a box across a floor, the energy from the person’s moving arm is transferred to the box, and the box and the floor become warm. During this process, what happens to energy?
It is increased.
It is conserved.
It is decreased.
It is created.
Answer:
B..it is conserved
Explanation:
Use the following information about Earth and its moon to determine the distance between them. Earth's mass = 6.0 x 1024 kg Moon's tangential speed = 1,025 m/s Earth's radius = 6.4 x 10 m Moon's mass = 7.3 X 1022 kg 4.6 x 106 m O 3.8 x 108 m O 3.9 x 1011 m
Answer:
3.8 × 108 m
Explanation:
Use formula: v^2 = G x m central / r
G = 6.77 e-11
Also, it was right on Edge.
Good luck!
The distance between Earth and its moon is 3.8×10⁸ m.
What is centripetal force?
A force that causes a body to follow a curved path is known as a centripetal force. It always moves in a direction that is the opposite of the body's velocity and in the direction of the immediate center of curvature of the path.
It is "a force by which bodies are dragged or driven, or in any manner tend, towards a point as to a center," according to Isaac Newton.
Given parameters:
Mass of the Earth: M = 6.0 × 10²⁴ kg.
Mass of the moon: m = 7.3 × 10²² kg.
Moon's tangential speed: v = 1,025 m/s
Let the distance between the center of Earth and the moon is r.
Hence,
GMm/r² = mv²/r
r = GM/v²
= 6.7 × 10 ⁻¹¹ × 6.0 × 10²⁴ / (1,025)²
= 3.82×10⁸ m.
Hence, by subtracting Earth's radius = 6.4 x 10⁶ m, we get, the distance between Earth and its moon is 3.8×10⁸ m.
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Which has greater density- 1 kg of water or 10kg of water?
Answer:
I believe that it will be 10kg of water
Explanation:
Because a measure of the amount of information on a storage medium (tape or disk). For magnetic tape it is the amount of information recorded per unit length of tape (bits per inch or millimeter); for a disk, a fixed number of bits per sector, sectors per track, and tracks per disk.
The density in both the case will be equal, just the difference will be in the volume they occupy.
What is density?In practice, density is the weight of a substance per unit volume. Water has a density of about 1 gram per milliliter, but this varies depending on temperature and whether or not substances are dissolved in it. Because ice is less dense than liquid water, it floats in your glass.
This allows many aquatic organisms to survive the winter. If ice were more dense than water, it would continue to freeze and sink until the entire lake was frozen.
Any amount of water has the same density. Whereas one gram of water has a volume of one milliliter, ten grams have a volume of ten milliliters.
Thus, the density will be same.
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Question 1
Ricardo came up with three different designs for paper airplanes. He would like to find out which design flies the farthest. Ricardo plans to fly each paper airplane five times. What step should Ricardo take after he flies each plane?
Answer:
B. measure the distance that the plane flew and record it
Explanation:
What is the acceleration of the object from 2s to 14s
how much hp does that fastest car in the world have
Answer:
Hennessey Venom F5. Power: 1600+ bhp. Price: $1.6 million.
Koenigsegg Regera. Power: 1500 bhp.
Bugatti Chiron. Power: 1479 bhp.
NIO EP9. Power: 1341 bhp. Price: $1.48 million.
create a formula giving the strength of the induced field (B) i terms of current (I) and the distance from the wire to the probe (d)
the thumb is what to the phalanges?
Answer:
A thumb only has one joint and two phalanges. The thumb is referred to as “the big finger".
Brainlist pls!
the court that has the executive power on review cases from regional trial courts
Answer:
courts of appeals
Explanation:
hope this helps
These are the reactant in a chemical equation: 6 CO2 + 6 H2O --> C6H12O6 + 6 O2
Answer:
Carbon Dioxide and Water.
Explanation:
This is the chemical formula for photosynthesis!
A book is sitting on a table. Which of the following is true about the table? O A. It is pushing up on the book. O B. It exerts no force on the book at all. O C. It is pulling down on the book. D. It can affect the mass of the book.
Answer:
yes it does exert a force, it pushes it up
Explanation:
this is called normal force
if it didn't exert a force the book would keep going down
according to newton every force has an equal amd opposite reaction
so the book exerts a force on the table and vice versa
hope this helped
Five independent measurements are made of the diameter of a cylinder. Results, in mm, are: 21.8; 21.6; 22.1; 21.9; 22.1. What should be the reported value of the cylinder's diameter?
Answer: 21.9 mm
Explanation:
Given that five independent measurements are made of the diameter of a cylinder. Results, in mm, are: 21.8; 21.6; 22.1; 21.9; 22.1. What should be the reported value of the cylinder's diameter?
The measurement of the diameter of cylinder is measured several time in order to reduce the uncertainty called random error.
The reported value of the cylinder's diameter should be the average or the mean value of the whole measurement.
That is
Mean = (21.8 + 21.6 + 22.1 + 21.9 + 22.1) ÷ 5
Mean = 109.5 ÷ 5
Mean = 21.9 mm
Therefore, the reported value of the cylinder diameter will be 21.9 mm
Atoms are made up of even smaller particles called ?
Answer:
Atoms are made up of even smaller particles called protons, electrons & neutrons (sub-atomic particles)
Atoms are made up of smaller particles called subatomic particles.
What is an Atom?
An atom is defined as the smallest indivisible particle of an element. It is made of subatomic particles which are:
NeutronProton ElectronNow the Neutron and Proton make up the nucleus which is at the core(middle) of the atom whole the electron rotates around the orbits that surrounds the nucleus.
The Neutron has no charge.
The Proton is positively charged.
The electron is negatively charged.
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Jacob is building a soapbox derby car. He hopes to win an upcoming downhill race in his neighborhood.
Which of the following should he take into consideration if his only concern is winning the race?
A. the color of the goggles that he wears
B. the shape of the car he makes
C. the mass of the materials he uses
D. the strength of the materials he uses