what do you call these sound waves whose frequency is above 20000 hertz

Answers

Answer 1

Answer:

Untrasound

Explanation:

Your welcome :)


Related Questions

One reason why it’s often easy to miss an action-reaction pair is because of the ________ of one of the objects.

Answers

Answer:

an action-reaction pair is because one of the objects is often much more massive and appears to remain motionless when a force acts on it. It has so much inertia, or tendency to remain at rest, that it hardly

A movie stunt double is supposed to run across the top of a train (in the opposite direction that the train is moving) and just barely jump off before reaching a tunnel, but after reaching the end of the train (starting from the front). If the train is moving at 150 km/hr, is 2 km long and the tunnel is 20 km away from the end (where the stunt double is going to jump from), how fast (in km/hr) will the stunt double need to run

Answers

Answer:

the required speed/velocity of the stunt double is 13.633 km/h

Explanation:

Given the data in the question;

velocity of train V = 150 km/h

distance = length of train + distance between the tunnel and the end

= 2 km + 20 km = 22 km

first we calculate time t taken by the train to reach the tunnel;

t = distance / velocity

we substitute

t = 22 km / 250 km/h

t = 0.1467 hr

so the velocity of the of the stunt double will be;

velocity = distance / time

we substitute

velocity = 2 km / 0.1467 hr

velocity = 13.633 km/h

Therefore, the required speed/velocity of the stunt double is 13.633 km/h

how do i get the answer for keplers law 3

Answers

Could you send the picture? So I can help you! Post the picture?

The membrane that surrounds a certain type of living cell has a surface area of 4.7 x 10-9 m2 and a thickness of 1.3 x 10-8 m. Assume that the membrane behaves like a parallel plate capacitor and has a dielectric constant of 4.7. (a) The potential on the outer surface of the membrane is 79.5 mV greater than that on the inside surface. How much charge resides on the outer surface

Answers

Answer:

Q = 1.2*10⁻¹² C

Explanation:

For any capacitor, by definition the capacitance C is equal to the relationship between the charge on one of the conductors and the potential difference between them, as follows:

       [tex]C = \frac{Q}{V} (1)[/tex]

For the special case of a parallel plate capacitor, just by application of Gauss' law to a rectangular surface half out of the outer surface, and half inside it, it can be showed that the value of the capacitance C is a parameter defined only by geometric constants, as follows:

       [tex]C = \frac{\epsilon_{0}*\epsilon _{r} * A}{d} (2)[/tex]

So, due to the left sides in (1) and (2) are equal each other, right sides must be equal too.Replacing ε₀, εr (dielectric constant), A, d and V by their values, we can solve for Q, as follows:

       [tex]Q =\frac{\epsilon_{0} * \epsilon_{r} *A* V}{d} = \frac{(8.85*(4.7)^{2}*79.5)e-24 (F/m*m2*V)}{1.3e-8m} = 1.2e-12 C = 1.2 pC (3)[/tex]

A 10-meter-long, 150 kg beam extends horizontally from a wall.One end of the beam is fixed to the wall and the other end is attached to the same wall by a cable that makes an angle of 60° with the horizontal. A 75 kg sign is hung from the beam 2.50 meters from the wall.


Determine the magnitude of the tension, in [N] on the cable necessary to keep the system in equilibrium.

Answers

Answer:

the magnitude of the tension on the cable necessary to keep the system in equilibrium is 1060.9 N

Explanation:

Given that;

Length L = 10 m

mass of beam m_b = 150 kg; weight W_beam = 150×9.8

mass of sign m = 75 kg

distance of sign hung from the beam from the wall d = 2.50 m

angle ∅ = 60°

g = 9.8 m/s²

Now,

Torque acting at one end of the beam will be;

[tex]T_{net}[/tex] = Tsin∅ × L - mg(d)-W × (L/2)

for equilibrium, [tex]T_{net}[/tex] = 0

therefore, 0 = Tsin∅ × L - mg(d)-W × (L/2)

so we substitute

Tsin(60°) × 10 - 75×9.8(2.50) - 150 × 9.8× (10/2) = 0

Tsin(60°) × 10 - 1837.5 - 7350 = 0

Tsin(60°) × 10 - 9187.5 = 0

Tsin(60°) × 10 = 9187.5

divide both side by 10

Tsin(60°) = 918.75

T × 0.8660 = 918.75

T = 918.75 / 0.8660

T = 1060.9 N

Therefore, the magnitude of the tension on the cable necessary to keep the system in equilibrium is 1060.9 N

The magnitude of the tension on the cable that keep the system in equilibrium is 1060.9 N.

 

Torque acting at one end of the beam,  

= Tsin∅ × L - mg(d)-W × (L/2)

When equilibrium  = 0  

Tsin∅ × L - mg(d)-W × (L/2) = 0

Where,

L - Length  =  10 m

m - mass of sign bord= 75 kg

g- gravitational accelaration = 9.8 m/s²

W - weight of beam =  150×9.8 = 1470 kg

 

Put the values in the formula,

Tsin(60°) × 10 - 75×9.8(2.50) - 150 × 9.8× (10/2) = 0  

Tsin(60°) × 10 - 1837.5 - 7350 = 0  

Tsin(60°) × 10 - 9187.5 = 0  

Tsin(60°) × 10 = 9187.5    

Tsin(60°) = 918.75  

T × 0.8660 = 918.75  

T = 918.75 / 0.8660  

T = 1060.9 N

Therefore, the magnitude of the tension on the cable that keep the system in equilibrium is 1060.9 N.

To know more about magnitude of the tension,

https://brainly.com/question/25403593

A ball is rolling across the floor. Why does the ball come to a stop?

The force of gravity stopped it.

The force of friction stopped it.

The normal force stopped it.

It had too much mass.

Answers

Explanation:

the notmal focrce stopped it.

Answer:

It's C the friction stopped it

Explanation:

Gravity has a little effect on it. However the main force stopping the ball rolling is the friction force of the floor. The ball will stop rolling when the velocity of the ball is the same as the velocity of friction force.

You serve a volleyball with a mass of 2.1 kg. The ball leaves your hand with a speed of 2.1 m/s. The
ball has ____
energy. Calculate it.

Answers

Answer:

4.6 Joules

Explanation:

K=1/2*MV^2

1/2 * 2.1kg * 2.1^2m/s

==4.6305  Joules

simplified to 4.6 Joules

A police officer is parked by the side of the road, when a speeding car travelling at 50 mi/hrpasses. The police car immediately pursues it, accelerating at a rate of 10 mi/hr per second.The road is fairly busy, so the officer will not go faster than a top speed of 70 mi/hr. How longwill it take before the officer catches up to the speeding car, and how far will it have travelled inorder to do so

Answers

Answer:

a) time taken to catch up with speeding car is 12.25 secs

b) the police car will travel 273.8 m to catch up with the speeding car

Explanation:

Given that;

speed of car [tex]V_{c}[/tex] = 50 mi/hr = 22.352 m/s

acceleration of police car = 10 mi/hr = 4.47 m/s²

[tex]V_{f}[/tex]  = 70 mi/hr = 31.29 m/s

Now time taken to reach maximum speed is t₁

so

[tex]V_{f}[/tex] =  [tex]V_{i}[/tex] + at₁

we substitute

31.29 = 0 + 4.47t₁

t₁ = 31.29 / 4.47

t₁  = 7 sec

now

d₁ = 0 + 1/2 × at₁²

d₁ = 0 + 1/2 × 0 + 4.47×(7)²

d₁ = 109.5 m

so distance travelled by the speeding car in time t₁  will be

[tex]d_{c}[/tex] = [tex]V_{c}[/tex] × t₁

we substitute

[tex]d_{c}[/tex] = 22.352 × 7

[tex]d_{c}[/tex]  = 156.46 m

now distance between polive car and speeding car

Δd =  [tex]d_{c}[/tex] - d₁

Δd = 156.46 - 109.5

Δd = 46.96 m

time taken to cover Δd will be

t₂ = Δd / ( [tex]V_{f}[/tex] - [tex]V_{c}[/tex] )

t₂ = 46.96 / ( 31.29 - 22.352 )

t₂ = 46.96 / 8.938

t₂ = 5.25 sec

distance travelled by the police in time t₂ will be

d₂ = [tex]V_{f}[/tex] × t₂

d₂ = 31.29 × 5.25

d₂ = 164.3 m

a) How long will it take before the officer catches up to the speeding car;

time taken to catch up with speeding car;

t = t₁ + t₂

t = 7 + 5.25

t = 12.25 secs

Therefore, time taken to catch up with speeding car is 12.25 secs

b)  how far will it have travelled in order to do so;

distance = d₁ + d₂

distance = 109.5 + 164.3

distance = 273.8 m

Therefore, the police car will travel 273.8 m to catch up with the speeding car

Imagine two cases: Block N is pushed by a hand, which exerts a constant force F_o. AND moves a distance d_ 0. In case 1, it takes a time T to move this distance. In a case 2, it takes time 2T to move this distance. The work done by the hand on N in case 1 is ____________ the work done by the hand in case 2.

a. greater than
b. less than
c, equal to

Answers

Answer:

C: Equal to

Explanation:

In calculating workdone, it is pertinent to know that it doesn't depend on time. The only relationship between work and time is when we want to calcite power where workdone/time taken = power.

Now, even if it took 2T time to love the same distance, it just means lesser force was used but still the workdone doesn't change.

Thus, the workdone in the first case will be equal to the workdone in the second case.

What is the difference between elastic PE and gravitational PE?

Answers

Elastic potential energy is kind of like pulling on something and then letting it go, with rubber bands, or a bow, or a slingshot, something with elastic properties.
Gravitational potential energy has to do with how high something is, and has to do with earth’s gravitational pull.
What ^he said! Have a good day!

3.
A student swings a ball attached to the end of a string 0.5m in length in
a vertical circle. The speed of the ball is 2m/s at the highest point and
6m/s at its lowest point: Find the acceleration of the ball at (ii) its highest
point and (ii) its lowest point.​

Answers

Answer:

I.72m/s²

II.8m/s²

Explanation:

acceleration equal velocity² divided by length

An electric field of intensity 3.25 kN/C is applied along the x-axis. Calculate the electric flux through a rectangular plane 0.350 m wide and 0.700 m long if the following conditions are true. (a) The plane is parallel to the yz-plane. N · m2/C (b) The plane is parallel to the xy-plane. N · m2/C (c) The plane contains the y-axis, and its normal makes an angle of 30.5° with the x-axis. N · m2/C

Answers

Answer:

[tex]\varphi_1= 796.25 N m^2/C[/tex]

[tex]\varphi_2= 0 N m^2/C[/tex]

[tex]\varphi_3=686.1 N m^2/C[/tex]

Explanation:

From the question we are told that

Electric field of intensity [tex]E= 3.25 kN/C[/tex]

Rectangle parameter Width [tex]W=0.350 m[/tex]  Length [tex]L=0.700 m[/tex]

Angle to the normal [tex]\angle=30.5 \textdegree[/tex]

Generally the equation for Electric flux at parallel to the yz plane [tex]\varphi_1[/tex] is mathematically given by

[tex]\varphi_1=EA cos theta[/tex]

[tex]\varphi_1=3.25* 10^3 N/C * ( 0.350)(0.700) cos 0[/tex]

[tex]\varphi_1= 796.25 N m^2/C[/tex]

Generally the equation for Electric flux at parallel to xy  plane [tex]\varphi_2[/tex] is mathematically given by

[tex]\varphi_2=EA cos theta[/tex]

[tex]\varphi_2=3.25* 10^3 N/C * ( 0.350)(0.700) cos 90[/tex]

[tex]\varphi_2= 0 N m^2/C[/tex]

Generally the equation for Electric flux at angle 30 to x plane [tex]\varphi_3[/tex] is mathematically given by

[tex]\varphi_3=EA cos theta[/tex]

[tex]\varphi_3=3.25* 10^3 N/C * ( 0.350)(0.700) cos 30.5[/tex]

[tex]\varphi_3=686.072219 N m^2/C[/tex]

[tex]\varphi_3=686.1 N m^2/C[/tex]

A Chinook salmon can jump out of water with a speed of 7.20 m/s . How far horizontally can a Chinook salmon travel through the air if it leaves the water with an initial angle of =29.0° with respect to the horizontal? (Neglect any effects due to air resistance.)
d=

Answers

Explanation:

The vertical component of the salmon's velocity is 7.2 m/s x sin 29 = 3.49 m/s

If g = 9.81 m/s^2, the salmon takes

(3.49 m/s) / (9.81 m/s^2) = 0.356 s to reach the highest point of its trajectory.

It takes another 0.356 s to fall back into the water again.

So the salmon is out of the water for a total of 0.712 s.

In this time the salmon travels horizontally with a velocity of 7.2 m/s x cos 29 = 6.30 m/s

We can now calculate the horizontal distance tavelled by multiplying the horizontal velocity by the time spent out of water;

0.712 s x 6.30 m/s = 4.48 m

Radioactive strontium (Sr) is harmful to humans. Strontium, when ingested by cows, can be introduced to milk through the process of replacing an element of the same group or family that has similar properties. Using the Periodic Table, which element do you think can be easily replaced by strontium in milk?

A: B


B: Ag


C: Ca


D: K

Answers

Answer:

Ca

Explanation:

It is

A car is traveling 100 km/hr. How many hours will it take to cover a distance of 850 km?

Your answer:

.118 hours


8.5 hours


7.5 hours


23 hours

Answers

Answer:

8.5 hours

Explanation:

8.5 hours because 850/100

A car is sitting still. It accelerates to a constant speed then it decelerates again to zero speed. While the car is accelerating how do the directions of the angular acceleration and angular velocity of one of the wheels compare

Answers

Answer:

in the acceleration process the quantity α and w must increase

the deceleration process the alpha quantity must constant  a direction opposite to the angular velocity

Explanation:

Acceleration and angular velocity are related to linear

           v = w xr

            a = αx r

The bold letters indicate vectors and the cross is a vector product, therefore if

we can see that the relationship between linear and angular variables is direct

therefore in the acceleration process the quantity α and w must increase as well as their linear counterparts

in the deceleration process the alpha quantity must constant as the linear acceleration and must have a direction opposite to the angular velocity

what occurred when the photosynthetic began to pump free oxygen into oceans?

Answers

when the photosynthetic began to pump free oxygen into oceans, the ocean had enough oxygen to support the life of non-photosynthetic organisms. So, non-photosynthetic organisms came into being.

A spider accelerates from a standstill to 5m/s in 10s. What is its acceleration?

Answers

Answer:

Acceleration = 0.5m/s²

Explanation:

Given the following data;

Final velocity = 5m/s

Time = 10 seconds

Since the spider started from rest, its initial velocity is equal to 0m/s

To find the acceleration;

In physics, acceleration can be defined as the rate of change of the velocity of an object with respect to time.

This simply means that, acceleration is given by the subtraction of initial velocity from the final velocity all over time.

Mathematically, acceleration is given by the equation;

[tex]Acceleration (a) = \frac{final \; velocity - initial \; velocity}{time}[/tex]

[tex]a = \frac{v - u}{t}[/tex]

Where,

a is acceleration measured in [tex]ms^{-2}[/tex]

v and u is final and initial velocity respectively, measured in [tex]ms^{-1}[/tex]

t is time measured in seconds.

Substituting into the equation, we have;

[tex]a = \frac{5 - 0}{10}[/tex]

[tex]a = \frac{5}{10}[/tex]

Acceleration = 0.5m/s²

How do protons neutrons and electrons differ

Answers

Answer/Explanation:

They have a relatively small mass compared to Protons and Neutrons. Protons are electrochemically positive in charge and the Neutrons are electrochemically neutral in charge.

Answer:

They differ because

Proton means positive charge

Electrons are negatively charged

Neutrons are neutral

A bottle of water at a room temperature of 21.0 C is placed into a refrigerator

with an air temperature of 4.5C. The thermal energy will move — *

A. from the cooler air to lower the temperature of the water to 4.5 C

B. in both directions until the temperature is equal in the water and the air

C. from the water to the air until the water temperature is zero degrees Celsius

O D. from the water to the air until the temperature is equal in both

Answers

Answer:

B. in both directions until the temperature is equal in the water and the air

Explanation:

When a warm body is in contact with a cool body , there is exchange of heat energy in both sides until there is attainment of equilibrium temperature . At this temperature both the body attains equal temperature . Initially rate of heat radiated by warm body is more than that from cool body , but after attainment of equilibrium , the rate becomes equal to each other . This is called dynamic equilibrium .

Hence option B is correct .


1. An object that does not give off its own light is called ____

2. The tilt of the Earth's axis creates the
_______

3. Both of the movements of the Earth causes interesting changes on the _______

4. The word solar means of the ______

5. When the Sun, the Earth and the Moon are in line there is an/a _____​

Answers

Answer:

1. non-luminous objects

sorry have to say the rest in the comments because brai.nly is doing the most for no reason

Explanation:

hope this helps sorry if it doesn't have a good rest of your day/afternoon :) ❤  

What is the momentum of a 100-kilogram fullback carrying a football on a play at a velocity of 3.5 m/sec.

Answers

Answer:

100 Kg * 3.5 m/sec = 350 Kg-m/s

Explanation:

Momentum= F= Δ(mv) with m= mass, v= velocity, and Δ the change in mass and velocity

In this problem you are given all the factors you need to solve the equation you simply just plug in  your mass (1,000 Kg) and Velocity (3.5m/s) and multiply them by each other to get your answer

What is the power of 600j of work done in 4 seconds?

Answers

Explanation:

Power = change in work/change in time

P = 600 joules/ 4 seconds

P= 150 watts

hope this helps :)

a student holds a 3.0kg mass in each hand while sitting on a rotating stool. when his arms are extended horizontally, the masses are 1.0m from the axis of rotation and he rotates with an angular speed of 0.75 rad/s. if the student pulls the masses horizontally to 0.30m from the axis of rotation, what is his new angular speed

Answers

Answer:

Explanation:

Due to change in the position of 3 kg mass , the moment of inertia of the system changes , due to which angular speed changes  . We shall apply conservation of angular momentum , because no external torque is acting .

Initial moment of inertia I₁ = M R² = 3  x 1 ² = 3 kg m²

Final moment of inertia I₂ = M R² = 3  x .3 ² = 0.27  kg m²

Applying law of conservation of angular momentum

I₁ ω₁ = I₂ ω₂

Putting the values ,

3 x .75 = .27 x ω₂

ω₂ = 8.33 rad / s

New angular speed = 8.33 rad /s .

g A boat is anchored 2000 ft from shore anddirects its searchlight towards an automobile travelingdown the straight road. At the particular moment whenthe distance rfrom the searchlight to the automobile is3000 ft, the automobile has speed 80 ft/s and increasesits speed at a rate of 15 ft/s2 down the road.Find the required angular velocity and angularacceleration of the boat's searchlight to track the automobile at this instant.(Answers: 0.018 rad/s CCW, 0.004 rad/s2 CCW)

Answers

Answer:

Explanation:

The distance of searchlight will act as radius R and velocity of car may be supposed to be tangential velocity v  . We are required to calculate  angular velocity ω .

v = 80 ft /s

R = 3000 ft

ω = v / R

= 80  / 3000 = .027 rad / s

For angular acceleration the formula is

angular acceleration α = a / R

a is linear acceleration = 15 ft / s²

α = 15 / 3000 = .005 rad / s².

The temperature of stars in the universe varies with the type of star and the age of the star among other things. By looking at the shape of the spectrum of light emitted by a star, we can tell something about its average surface temperature.i)If we observe a star's spectrum and find that the peak power occurs at the border between red and infrared light, what is the approximate surface temperature of the star

Answers

Answer:

  T = 3.6 10³ K

Explanation:

A good way to calculate the surface temperature of a star is to approximate it as a black body, and use Wien's displacement law.

            λ T = 2,898 10⁻³

In this case they tell us that the light from the star is between red (700nm) and light infrared (2500nm) suppose that the radiation is

            λ = 800 nm (near infrared)

             T = 2,898 10⁻³ /λ

             T = 2,898 10⁻³/ (800 10⁻⁹)

             T = 3.6 10³ K

PLEASE I REALLY NEED HELP!
Question 6
If the car traveled a total of 1,200 meters during this test, what was the average speed of the car? Include the
correct units.

Answers

Answer:

[tex]v=\dfrac{1200}{t}\ m/s[/tex]

Explanation:

Given that,

The car traveled a total of 1,200 meters during this test.

We need to find the average speed of the car. The average speed of the car is given by total distance covered divided by the time taken. So,

[tex]v=\dfrac{1200}{t}\ m/s[/tex]

But putting the value of t we can find the average speed of the car.

What is a measure of how much matter an object is made of?

Answers

Answer:

grams

Explanation:

First you lift an object from the floor onto a shelf. Then you move the object back to the floor. do you perform the same amount of work each time? Explain.

Answers

Not really, let’s say a gallon of milk, that’s heavy, so it would be harder to lift it than to put it down. Right? Hope this helps :>

A steel ball (mass = 50 grams) and a plastic ball of the same dimensions (mass = 10 grams) are dropped from the same height at the same time. Which of the following will occur? (ASSUME NO AIR RESISTANCE)
a. the plastic ball will hit the ground before the steel ball hits the ground
b. the steel ball will hit the ground before the plastic ball hits the ground
c. the steel ball and the plastic ball will hit the ground at the same time

Answers

C at the same time because there's no air resistance
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