4. When a key on piano is pressed, a sound is heard. What produces this sound?
A. the vibrating key of the piano
B.
The Vibrating String Of Piano
C. the finger pressing the piano key
D. the air molecules inside the piano

Answers

Answer 1

Answer:

D

Explanation:

since we press the key , air molecules ate presented and sound wave is formed what we hear.

Answer 2

Answer:

B

Explanation:

the vibrating string of piano

Related Questions

(Ecology) Food Chain lab Gizmo:
Before you interact with the simulation, what are your expecations? How will the food chain be effected if one organisim's population is altered? In your response, select one organisim (grass, rabbit, snake, hawk) and give a 3 sentence response on how you think a change in population of this organisim will impact the rest of the food chain.

Answers

Answer:

If the population of rabbits was altered then the food chain would be affected because if the population decreased then the animals that prey on rabbits wouldn't have as much food as they used to so the predators of the rabbits would decrease. If the population increased then the animals that prey on rabbits would increase. Overall, if rabbits had a change in population then the food chain would become effected, because if rabbits decrease then their predators decrease in population as well, the same goes for an increase in population.

(hope this helped!)

A train was moving at 50m/s and slow down to 20 m/s in 50 seconds, what was its acceleration?

Answers

Answer:

-0.6 m/s^2

Explanation:

a = change in velocity / time

change in velocity = 50 m/s - 20 m/s = 30 m/s

time = 50 s

30 m/s / 50s

= 0.6 m/s^2

because it is decelarating, it will be -0.6 m/s^2

What causes mechanical wave motion

Answers

Answer:

A disturbance or vibration in matter

Explanation:

Answer:

A mechanical wave is a distance in matter that transfer energy through the matter. A mechanical wave starts when matter is disturbed. A source of energy is needed to disturb matter and start a mechanical wave.

A prism is often used to show the different wavelengths of light or colors that can be found in white light. In one paragraph, using your own words, explain how the prism causes these colors to appear. Be sure to use proper spelling, grammar, and punctuation.

Answers

Answer:

A prism causes the different wavelengths of light or colors that can be found in white light because the prism is white, and white light contains all colors in the visible light spectrum. So an object that reflects all the colors in the visible light spectrum will appear white in color because white light contains all colors in the visible light spectrum.

Explanation:

I hope this helps! I just did a test with this question and I got the answer right! This is the answer that I put. Good luck :)

compare and contrast current and static electricity plz help.

Answers

Static

Type of electron movement: random

path of electrons: unpredictable

duration flow: short

usefulness: stattionery objects

Current

Type of electron movement: steady in a given direction

Path of electrons: can be directed

Duration of flow: long

Usefulness: can power appliances

Note: This is a few notes I know about it sorry if its not what you are looking for This is all the info I have

I really need help

John's mass is 55kg when he is standing on the edge of a diving
board 24m high. a. Find his mechanical energy.

What is it?

Answers

Answer:

E = 12.9 kJ

Explanation:

Given that,

Mass of John, m = 55 kg

It is standing on the edge of a diving board which is at a height of 24 m.

We need to find his mechanical energy. The mechanical energy of John is equal to its potential energy such that,

E = mgh

E = 55  kg × 9.8 m/s² × 24

E = 12936  J

or

E = 12.9 kJ

So, his mechanical energy is equal to 12.9 kJ.

What kind of energy was used to move the toy car?​

Answers

Answer:

kinetic energy

Explanation:

Motors change electrical energy into kinetic energy. The spinning movement of the motor is used to do work, for example, the wheels on a toy car.

Answer:

hope this works

Explanation:

Kinetic energy is defined as the energy of a moving object.

A thrown football, a speeding automobile, a marathon runner, or a rock falling from a cliff, are examples of objects that have kinetic energy.

A skydiver jumps from a stationary helicopter and reaches a steady vertical speed. She then opens her parachute. Which statement about the falling skydiver is correct?

A As her parachute opens, her acceleration is upwards.
B As she falls at a steady speed with her parachute open, her weight is zero.
C When she accelerates, the resultant force on her is zero.
alda
D When she falls at a steady speed, air resistance is zero.

Answers

Answer:

A) As her parachute opens, her acceleration is upwards.

Explanation:

The acceleration is the rate of change of the velocity.

Thus, if you have positive velocity and positive acceleration, your velocity increases

If you have positive velocity and negative acceleration, then your velocity decreases.

(The opposite happens when you have negative velocity).

Now, when the skydiver is falling, her velocity is downwards.

When she opens her parachute, her velocity downwards decreases.

This means that when she opens her parachute, she will have an acceleration in the opposite direction to her velocity, then at this point her acceleration is upwards.

We can conclude that the correct option is:

A) As her parachute opens, her acceleration is upwards.

Kamal said the distance from the top of the balloon to the ground in the Example is Ï···· 353 ft. What mistake might Kamal have made? 1 2

Answers

Complete question is;

Kamal said the distance from the top of the balloon to the ground in the Example image attached is √353 ft. What mistake might Kamal have made?

Answer:

the mistake Kamal made is that she probably used 17 ft as the perpendicular side of the triangle with b as the hypotenuse instead of using 17ft as the hypotenuse

Explanation:

From the image attached, we can see that the distance from the top of the balloon which is blue in color to the ground is denoted by "b".

Now the triangle is a right angle triangle with hypotenuse = 15ft + 2ft = 17 ft; the adjacent side = 8 ft, while the opposite side is "b".

Thus, we can use pythagoras theorem to solve this as;

b = √(17² - 8²)

b = √(289 - 64)

b = √225

b = 15ft

However,we are told Kamal got b as √353 ft.

From inspection of the calculations we just did, if we had used addition instead of subtraction, we would have gotten b = √353 ft.

Thus, we can under that the mistake Kamal made is that she probably used 17 ft as the perpendicular side of the triangle with b as the hypotenuse instead of using 17ft as the hypotenuse.

An astronaut lands on an alien planet. He places a pendulum (L = 0.200 m) on the surface and sets it in simple harmonic motion, as shown in this graph.

(a) What is the period and frequency of the pendulum’s motion?
(b) How many seconds out of phase with the displacements shown would graphs of the velocity and acceleration be?
(c) What is the acceleration due to gravity on the surface of the planet in? Determine the number of g-forces.
Show any necessary calculations.

Answers

I think b or c sorry

Who discovered natural magnet for the first time?​

Answers

Answer: Magnes



Explanation: Magnes found that the nails and buckle of his sandals and the tip of his staff were attracted to the rock he was standing on. He dug up the Earth to find lodestones. Lodestones contain magnetite, a natural magnetic material Fe3O4.

can someone help me pls

Answers

Answer: food, female water

Explanation:

Can I have brainliest

Answer :  dog horse  cat lion deer  moose tiger cheetah hippopotamus zebra rabbit  penguin dolphin  shark fish

Explanation:

A wave with a frequency of 1.1 Hz travels through deep water at a speed of 5.7 m/s. When the wave enters shallow water, its speed slows to 3.2 m/s. What is the wavelength of the wave in the shallow water?

Answers

Answer:

The wavelength of the wave in shallow water is 2.91 m.

Explanation:

Given;

frequency of the wave, f = 1.1 Hz

speed of the wave in deep water, v₁ = 5.7 m/s

speed of the wave in shallow water, v₂ = 3.2 m/s

The wavelength of the wave in the deep water is calculated as;

λ₁ = v₁/f

λ₁ = 5.7 / 1.1

λ₁ = 5.18 m

The wavelength of the wave in the shallow water is calculated as;

λ₂ = v₂/f

λ₂ = 3.2 / 1.1

λ₂ = 2.91 m

Therefore, the wavelength of the wave in shallow water is 2.91 m.

explica de que tipo es cada oración según la actitud del hablante

Answers

Answer:

Según la actitud del hablante las oraciones se clasifican en enunciativas, interrogativas, etc. ... adverbios o expresiones que complementan a toda la oración (COr): ojalá, quizá.

Explanation:

Multiple Choice
Which is the best reason to be wary of those you talk to on the Internet?
A. They may not be who they say they are.
B. You don't know where they live.
C. You don't know their favorite foods.
D. They may not be in the same grade as you.

Answers

I would see a you get it right
A they might not be who they say they are

A planet orbits a sun in a clockwise elliptical orbit as shown in the diagram below
Bubble in the letter representing the position or choose e if it is constant

At which position does the planet have the greatest gravitational energy?

Answers

Answer:

Greatest gravitational energy is at "C".

The planet has to do work "against" the field to get to "C".

Also, if m v R (angular momentum) is constant then as R increases v must decrease for this term to be constant and KE = 1/2 M v^2  must decrease also to get to point C.

HELP!!!!!!!!!
A toy car has a motor capable of moving the car at 10m/s up a 35 degree ramp. If the motor exerts a force of 500N to the car, what is the power rating of the motor in kW?

Answers

Answer:

4.096 kW

Explanation:

Applying,

P = Fvcos∅................. Equation 1

Where P = Power of the motor, F = Force exerted on the motor, v = Velocity, ∅ = angle.

From the question,

Given: F = 500 N, v = 10 m/s, ∅ = 35°

Substitute these values into equation 1

P = 500×10×cos35°

P = 4095.8 W

P = 4.096 kW

Hence the power rating of the moto in kW is 4.096 kW

Nanotechnology is currently used in electronics for


organ repair, data storage, and wires.

organ repair, quantum dots, and carriers.

data storage, OLEDs, and wires.

carriers, OLEDs, and skin transplants.

Answers

Answer:

data storage, OLEDS, and wires

Explanation:

Nanotechnology is currently used in electronics for data storage, OLEDs, and wires. Option C is correct.

What is nanotechnology?

Nanotechnology is the near-atomic manipulation of matter to create new structures, materials, and gadgets.

The technique offers scientific improvement in a variety of fields, including medical, consumer goods, energy, materials, and manufacturing.

Nanotechnology is currently used in electronics for data storage, OLEDs, and wires.

Hence, option C is correct.

To learn more about the nanotechnology, refer;

https://brainly.com/question/11946759

#SPJ2

How are wave properties and energy related?
EXPLAIN

Answers

Answer:

The higher the amplitude, the higher the energy. To summarise, waves carry energy. The amount of energy they carry is related to their frequency and their amplitude. The higher the frequency, the more energy, and the higher the amplitude, the more energy.

You have viewed multiple unknown astronomical objects in this lab activity. In all tests, what was your test variable (independent variable)?

The amount of an element in each object
The type of elements in each spectrum
The astronomical object viewed by the spectrometer

Answers

Answer:

Could you give information about the lab

Explanation:

Answer:

The spectrum of each astronomical object

Explanation:

I took the test and got it right

What work is done by a forklift raising a 574 kg crate to a height of 1.3m in a time of 2.0 seconds?

Answers

Answer: [tex]7312.76\ J[/tex]

Explanation:

Given

Mass of crate is m=574 kg

The crate is raised up to a height of 1.3 m

time taken t=2 s

Work done to raise the crate is equal to the change in its potential energy

[tex]\Rightarrow \text{Work done W=}mgh\\\Rightarrow W=574\times 9.8\times 1.3\\\Rightarrow W=7312.76\ J[/tex]

What is an important difference between nanotechnology and microtechnology?

Nanotechnology shows results of quantum mechanics, but microtechnology does not.
Microtechnology shows results of quantum mechanics, but nanotechnology does not.
Microtechnology is used to make products, but nanotechnology is not.
Nanotechnology is used to make products, but microtechnology is not.

Answers

Answer:

A) Nanotechnology shows results of quantum mechanics, but microtechnology does not.

Explanation:

Edge 21 test

The difference between nanotechnology and micro technology is nanotechnology shows results of quantum mechanics, but micro technology does not.

What are the differences between micro-technology and nanotechnology?

Micro technology:

      The technology that can be featured completely in a microscopic scale is known to be micro - technology. This technology that contribute to design, use components, devices that involves in small size. These were done significantly in smaller features.

Nanotechnology:

      Nanotechnology is the field of applied science and technology that can be measured through nanoscale. Nanotechnology is helping to considerably improve, industry sectors - information technology, homeland security, medicine, transportation, energy, food safety, and environmental science, among many others.

Thus, Nanotechnology shows results of quantum mechanics but micro-technology does not. Option A is the correct answer.

Learn more about micro and nano technology,

https://brainly.com/question/24723558

#SPJ5

An 16 m tall vase is located 50 m in front of a lens. An image is produced
20 m away from the lens. What is the focal length?

Answers

Answer:

f = 14.28 m

Explanation:

Given that,

Object distance, u = -50 m

The image distance from the lens, v = +20 m

We need to find the focal length of the lens. Let the focal length is f. Using the lens formula,

[tex]\dfrac{1}{v}-\dfrac{1}{u}=\dfrac{1}{f}[/tex]

Put all the values,

[tex]\dfrac{1}{20}-\dfrac{1}{(-50)}=\dfrac{1}{f}\\\\f=14.28\ m[/tex]

So, the focal length of the lens is equal to 14.28 m.

An air track car with a mass of 0.55 kg and velocity of 5.8 m/s to the right collides and couples with a 0.45 kg car moving to the left with a velocity of 3.9 m/s. What is the combined velocity of the cars just after the collision?

Answers

Explanation:

Given:

m1 = 0.55 kg

m2 = 0.45 kg

vi1 = +5.8 m/a

vi2 = -3.9 m/a

Solve for V

m1vi1 + m2vi2 = (m1 + m2)V

(0.55 kg)(+5.8 m/s) + (0.45 kg)(-3.9 m/s) = (0.55 + 0.45)V

V = +1.46 m/a

This means that the combined mass after the collision is moving to the right at 1.46 m/s

how does current flowing through a resistor affect the temperature​

Answers

The answer is... When electrical current flows through a type or kind of material, the electrons come in contact with the small atoms of the material and their collision produces heat. When the flow is through or going through a resistor, the resistance is offered to the flow and the collisions will generate heat. This is the reason why temperature rises. Hope this helps!

differences between weightlessness in space and weightlessness in earth​

Answers

Answer:

it depends on a person's own weight

Answer:

The gravity is roughly the same. The inverse square law applies to gravity and that means that being 60 miles above Earth is about the same as being on Earth. The thing is, they are going really fast in an orbit and thus falling around the Earth. The weightlessness comes from a sort of cancellation of gravity pulling them down and their going perpendicular to that force. The forces are cancelling and making them relatively “weightless”. It’s not really weightlessness but just an equilibrium reached between the two accelerations of gravity and their motion against the pull of the Earth.

Explanation:

which instrument determine the purity of milk​

Answers

Answer:

Milk Lactometer

Milk Lactometer: A lactometer is an instrument that is used to check for the purity of milk by measuring its density.

lactometer is used to determine the purity of milk

hope it is helpful to you

True or false: balanced forces are important for a hoverboard to float.
True
False

Answers

Answer:

True its got to be true

Explanation:

how else does a hoverboard float lol

Answer:

It's true

Explanation:

So true..

Why is diffraction used in soil profiles?

Answers

Answer:X-ray diffraction (XRD) is the technique most heavily relied on in soil mineralogical analysis. X-ray diffraction is a technique that provides detailed information about the atomic structure of crystalline substances. It is a powerful tool in the identification of minerals in rocks and soils.

Explanation:

XRD is used to identify the minerals composing clay-rich, hydrothermally altered rocks that occur on several Cascade volcanoes. Such rocks are believed to play an important role in the generation of large landslides and mudflows. XRD is used to analyze saline minerals, including borates.


Susan gently pushes the tip of her finger against the eraser on her pencil and the pencil does not move. Which of the
following figures best illustrates the interaction of forces between Susan's finger and her pencil?

Answers

Answer: D. ➡️⬅️

Explanation: I just knew the answer ;)

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