Which speed is at at the sound barrier?

Every moving object has kinetic energy.

The kinetic energy a moving object has is

(half of its mass)

multiplied by

(the square of its speed).

Answer:

Read below!

Explanation:

You can watch the sun wheel across the sky during the day, and the stars at night. Focus a telescope on any star besides the north star--especially southern stars--and you can watch them drift across your field of view.  

An alternative explanation is that all the stars are painted on (or holes in) some canopy that rotates around the earth. This explanation does not account for the motion of the "wanderers," or planets, as the Greeks called them, or for the path of the moon among the stars.  

As we know the stars are massive bodies of significant and varying distance to the earth, the notion they all swing around us in unison seems highly implausible

Answer:

A would definately be the correct answer

Explanation:

Answer: A. Proteins expressing color in butterfly wings mutate to create camouflaging abilities of butterflies.

Explanation:

Adaptation can be define as the changes occurring in living organisms in their physiology, morphology, and genomic. These adaptations allow organisms to survive in adverse environment.

A. is the correct option. It is an example of physiological adaptation. The color of butterfly wings will change due to protein expression. Thus help in camouflaging the predators by color change.

Answer:

27 J/(mol • K)

Explanation:

γ = Cp / Cv

We're given γ and we need to find Cp (heat capacity at constant pressure) per mole.  First we need to find Cv (heat capacity at constant volume).  Cv is defined as:

Cv = Cp − nR

where n is the number of moles and R is the ideal gas constant.

So:

γ = Cp / (Cp − nR)

γ (Cp − nR) = Cp

γ Cp − γnR = Cp

(γ − 1) Cp = γnR

Cp / n = γR / (γ − 1)

Given γ = 1.44 and R = 8.314 J/mol/K:

Cp / n = (1.44) (8.314 J/mol/K) / (1.44 − 1)

Cp / n = 27 J/mol/K

Answer:

The baseball's kinetic energy is 120 joules.

Explanation:

The kinetic energy is defined as:

[tex]k_{e} = \frac{1}{2}mv^{2}[/tex]  (1)

Where [tex]k_{e}[/tex] is the kinetic energy, m is the mass and v is the velocity.

The kinetic energy represents how much energy have an object as a consequence of its movement.

For the case of a baseball (m = 0.15 kg, v = 40.0 m/s):

[tex]k_{e} = \frac{1}{2}(0.15kg)(40.0m/s)^{2}[/tex]

[tex]k_{e} = 120 Kg.m^{2}/s^{2}[/tex]

But 1 j = [tex]kg.m^{2}/s^{2}[/tex]

[tex]k_{e} = 120 j[/tex]

Hence, baseball's kinetic energy is 120 joules.

"When we swim, we apply force and push the water backward with the help of our hands. In response to this action, the water pushes us forward with an equal force. Thus, in order to move forward and swim, the swimmer pushes the water backward."

-Newton's 3rd law

If the voltage impressed across the ends of the circuit were doubled then its new current would be 120 milliAmps

Ohm's law claims that the voltage across a conductor is directly proportional to the current flowing through it.

This current-voltage connection may be expressed mathematically as,

The Equation of Ohm's Law is given as;

[tex]\rm V=IR \\\\ I=\frac{V}{R} \\\\[/tex]

If the resistance is constant. The current is directly propotional to the voltage;

If the voltage value is doubled the value of the current in the circuit ios is also doubled. The value of the new current will be;

[tex]\rm I' = 60 \times 2 \\\\ \rm I' = 120 \ mA[/tex]

Hence if the voltage impressed across the ends of the circuit were doubled then its new current would be 120 milliAmps

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Final answer:

According to Ohm's Law, if the voltage in a circuit is doubled while the resistance remains constant, the current would also double. Therefore, if the initial current is 60.0 milliAmps and the voltage doubles, the new current would be 120.0 milliAmps.

Explanation:

The question deals with Ohm's Law, which is a fundamental principle in physics that describes the relationship between voltage, current, and resistance in an electrical circuit. According to Ohm's Law, the current in a circuit is directly proportional to the voltage across it and inversely proportional to the resistance of the circuit. Thus, if the voltage in a circuit is doubled while the resistance remains constant, the current would also double.

Given that the initial current in the wires of a circuit is 60.0 milliAmps, and if the voltage impressed across the ends of the circuit were doubled without any change in its resistance, the new current would be 120.0 milliAmps.

Answer:

3.605N

Explanation:

From the diagram attached, the resultant force can be calculated using pythagoras theorem,

R² = F1² + F2²

R² = 3² + 2²

R² = 9 + 4

R² = 13

R = 3.605N

Note: the square root of R was taken

Answer:

The total charge that passes through the player in 900s is Δq = 108C

Explanation:

Charge and current

The concept of electric charge is the fundamental principle to explain all electrical phenomena. Also, the basic quantity in an electrical circuit is the electric charge. All people experience the effect of electric charge when they try to take off a wool sweater and it is stuck to the body or when they go through a carpet and receive an electric shock.

Charge is an electrical property of the atomic particles of which matter is composed, measured in coulombs (C).

Electric current is the rate of change of the load with respect to time,  measure in amperes (A).

Mathematically, the relationship between current i, charge q and time t is:

i = dq/dt

Δq = i Δt

Δq = 0.120A x 900s = 108C

Answer:

800 N/C to the right

Explanation:

The relationship between electric force, electric field and charge is

[tex]E=\frac{F}{q}[/tex]

where

E is the electric field

F is the force acting on the charge

q is the charge

In this problem, we have

[tex]F = 0.040 N[/tex] is the force

[tex]q=+50 \mu C=+50 \cdot 10^{-6}C[/tex] is the charge

Substituting into the formula, we find the electric field magnitude

[tex]E=\frac{0.040 N}{+50 \cdot 10^{-6}C}=800 N/C[/tex]

Concerning the direction:

- The electric field and the force have same directions if the charge is positive

- The electric field and the force have opposite directions if the charge is negative

Here the charge is positive, so the electric field has same direction as the force: therefore, to the right.

Answer:

B.

The explanation of the relationship between load and extension is not in Hooke's Law.

Explanation:

Answer:

theory

Explanation:

I just took the test! hope this helps!

Answer:

2.25 N upwards

Explanation:

Answer:

800 N/C to the right

Explanation:

The equation that relates force on a charge, electric field and charge is

[tex]F=qE[/tex]

where

F is the force acting on the charge

q is the charge

E is the electric field

In this problem, we have

[tex]E=15 N/C[/tex] is the electric field

[tex]q=-0.15 C[/tex] is the charge

Substituting into the formula, we find the force

[tex]F=(-0.15 C)(15 N/C)=-2.25 N[/tex]

Concerning the direction:

- The electric field and the force have same directions if the charge is positive

- The electric field and the force have opposite directions if the charge is negative

Here the charge is negative, so the electric field has opposite direction to the force: therefore, it must be upwards.

Answer:

Electric charge

Like; opposite

Faster

True

True

positive to negative

Explanation:

Answer: The answer is C. 4.9 sec.

Explanation:

Answer:

c) 4.9 s

Explanation:

Young's modulus of aluminium is given as

[tex]Y = 69 \times 10^9 pa[/tex]

density of aluminium is given as

[tex]\rho = 2700 kg/m^3[/tex]

now the speed of sound in aluminium is given as

[tex]v = \sqrt{\frac{Y}{\rho}}[/tex]

[tex]v = \sqrt{\frac{69 \times 10^9}{2700}}[/tex]

[tex]v = 5055.3 m/s[/tex]

now the time taken by the sound to travel a distance of d = 25 km

[tex]t = \frac{d}{v}[/tex]

[tex]t = \frac{25 \times 10^3}{5055.3}[/tex]

[tex]t = 4.9 s[/tex]

Answer:

B) protons and neutrons.

Explanation:

The protons and neutrons are located in the nucleus of the atom and represent most of the 'mass' of the atom, that's their count that determine the 'mass' of an atom (like 12 for Carbon).

The electrons rotate around the nucleus and have a negligible mass.

Answer:

B

Explanation:

Protons have a positive charge, while neutrons have a no charge (neutral). There two components make up the nucleus. While electrons go around the nucleus creating an electron cloud.

The electron is the subatomic particle that determines an element's reactivity, with the configuration of the outermost or valence shell playing a key role in how readily an element undergoes chemical reactions.

The subatomic particle responsible for determining the reactivity of an element is the electron. The electrons in the outermost subshell, or valence shell, have the most significant interaction with other atoms, as they are farthest from the nucleus. An element is chemically reactive if its valence shell can easily accept or give up electrons. For instance, noble gases like helium and neon have a full valence shell and are very stable—they do not react easily due to their high ionization energies and unwillingness to accept an additional electron. On the other hand, elements like hydrogen have an incomplete valence shell, making them more reactive as they seek stability through reactions with other elements.

Answer:

200000 cm are in 2 km

Explanation:

Answer:

200000 cm are in 2 km

hope this helps pls make this the brainliest

Answer:

Explanation:

That is exactly what it does. That's how it is set up.

True

An electrocardiogram (ECG or EKG) is a diagnostic tool used to record the electrical activity of the heart. It involves the use of an electrocardiograph and electrodes. However, it has certain limitations and cannot reveal the effectiveness of the heart's pumping action.

An electrocardiogram (ECG), also often abbreviated as EKG, is a recording of the electrical activity of the heart that can be used to diagnose irregular heart function. Through the placement of surface electrodes on the body, the complex, compound electrical signal of the heart can be recorded. These signals are created from the processes of depolarization and repolarization, especially in the heart.

The standard electrocardiograph uses between 3 and 12 leads to capture this information. These leads may refer to the cables from the electrodes to the electrical recorder, but typically, it refers to the voltage difference between two electrodes. Sometimes, a patient might need to wear a portable device known as a Holter monitor to continuously monitor the heart's electrical activity.

It's important to note that the ECG has limitations. For instance, not all areas suffering a myocardial infarction (MI) may show up on the ECG. It also will not reveal the effectiveness of the heart's pumping action, which requires further tests such as an echocardiogram or nuclear medicine imaging.

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Answer:

18 m, 7.9 m

Explanation:

In the y direction:

y = y₀ + v₀ᵧ t + ½ aᵧ t²

0 = 0 + (v₀ sin 45°) t + ½ (-g) t²

0 = t (v₀ sin 45° - ½ g t)

t = 0, t = 2v₀ sin 45° / g

In the x direction:

x = x₀ + v₀ t + ½ at²

x = 0 + (v₀ cos 45°) t + ½ (0) t²

x = v₀ cos 45° t

Substituting for t:

x = v₀ cos 45° (2v₀ sin 45° / g)

x = v₀² / g

When g = 9.80 m/s², x = 3.0 m:

3.0 = v₀² / 9.80

v₀² = 29.4

On the moon, when g = 9.80/6:

x = 29.4 / (9.80 / 6)

x = 18 m

As you can see, x is inversely proportional to g, so 1/6 the gravity means 6 times the distance.  So on Mars:

x = 3 / 0.38

x = 7.9 m

Answer:

Hypocalcemia is the correct answer.

Explanation:

This disease, hypocalcemia, is usually known as calcium deficiency disease, which happens when calcium levels in the blood are low. If this disease is not taken care of properly, it can lead to cataracts, alteration in the brain, or even osteoporosis (the bones become brittle.)

Answer:

-300 Hz

-450 Hz

Explanation:

As we know that frequency of nth harmonic mode is known as

[tex]f_n = \frac{nv}{2L}[/tex]

now we know that for fundamental mode of frequency we will have

n = 1

[tex]f_o = \frac{v}{2L}[/tex]

so we will have

[tex]f_n = n f_o[/tex]

now given that

[tex]f_o = 150 Hz[/tex]

and also we have

n = integer

so we will have

n = 2

[tex]f = 300 Hz[/tex]

n = 3

[tex]f = 450 Hz[/tex]

Answer:

300 and 450

Explanation:

The suns gravity pulls on the planets and keeps them in place. Its gravitational pull puts them in orbit around the sun

The role of the sun's gravity is to keep the planets in place.

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i believe it's C but i'm not completely sure

The answer is a change in the direction of light when it goes from one medium into a different medium.

1) A. 2

The electrostatic force between two objects is given by:

[tex]F=k\frac{q_1 q_2}{r^2}[/tex]

where

k is the Coulomb's constant

q1 and q2 are the charges of the two objects

r is the separation between the two objects

In this problem, the charge of one object is doubled, so

[tex]q_1' = 2q_1[/tex]

Therefore the new force is

[tex]F'=k\frac{q_1' q_2}{r^2}=k\frac{(2q_1)q_2}{r^2}=2(\frac{kq_1 q_2}{r^2})=2F[/tex]

So, the force will double.

2) D. 1/4

Using the same formula, the electrostatic force between the two objects is:

[tex]F=k\frac{q_1 q_2}{r^2}[/tex]

In this problem, the distance between the two objects is doubled, so

[tex]r' = 2r[/tex]

Therefore the new force is

[tex]F'=k\frac{q_1 q_2}{(r')^2}=k\frac{q_1 q_2}{(2r)^2}=\frac{1}{4}(\frac{kq_1 q_2}{r^2})=\frac{F}{4}[/tex]

So, the force will decrease to 1/4 of its original value.

3) 4/9

Using the same formula, the electrostatic force between the two objects is:

[tex]F=k\frac{q_1 q_2}{r^2}[/tex]

In this problem, the amount of charge on both objects doubles, so

[tex]q_1' = 2q_1[/tex]

[tex]q_2' = 2q_2[/tex]

Also, the distance is tripled

[tex]r' = 3r[/tex]

Therefore the new force is

[tex]F'=k\frac{q_1' q_2'}{(r')^2}=k\frac{(2q_1) (2q_2)}{(3r)^2}=\frac{4}{9}(\frac{kq_1 q_2}{r^2})=\frac{4}{9}F[/tex]

So, the force will decrease to 4/9 of its original value.

Answer: The correct answer is False.

Explanation: The term "raw data" refers to the data that has not been processed or "clean" for use. A scientific journal is a type of publication that specializes in publishing new researches of the scientific field. These researches contain information, that is considered the end product of processing the raw data. It is most likely that raw data would not be used as it comes in published scientific articles.

Answer: It's false

Explanation:

I got it right on edge.

1. Rocks near mid-ocean ridge were younger than rock near trenches. Rocks away from the mid-oceanic ridges are relatively older than those near it.  

Additionally, the older rocks are denser and thicker compared to thinner and less dense rocks near the mid-oceanic ridge.

2. Matching bands of magnetic rocks were found on either side the mid-ocean ridge; bands like tree rings - record changes in earth's magnetic field over time.

This means sea floor contains different rocks based on ages and are positioned equally in opposite directions. This indicates that there is constant movement and spreading of rocks on the ocean floor.

3. Earthquake data showed oceanic crust is sinking on to the mantle at trenches.  

Keywords: Seafloor spreading, evidence of seafloor spreading  

Level: High school  

Subject: Geography  

Topic: Geology  

Sub-topic: Seafloor spreading  

The main evidence for sea-floor spreading comes from several sources of geological and geophysical data, which collectively support the idea that new oceanic crust is continually forming at mid-ocean ridges and spreading away from these ridges over time.

Some of the key evidence for sea-floor spreading includes:

1. Oceanic Bathymetry: The mapping of the ocean floor using sonar and other techniques has revealed the existence of mid-ocean ridges, underwater mountain ranges that extend for thousands of kilometers through the world's oceans. These ridges exhibit a symmetrical pattern of magnetic anomalies on either side, indicating a continuous process of seafloor spreading.

2. Paleomagnetic Evidence: Scientists have discovered that the rocks making up the ocean floor contain records of the Earth's past magnetic field. As the magma cools and solidifies at mid-ocean ridges, magnetic minerals within the rocks align with the prevailing magnetic field at the time. By studying the magnetic orientation of these rocks, scientists found that the magnetic patterns are symmetrical on either side of mid-ocean ridges, supporting the idea of sea-floor spreading.

3. Age of Oceanic Crust: Radiometric dating of rock samples collected from the ocean floor reveals that the rocks get progressively older as one moves away from mid-ocean ridges. The youngest rocks are found near the ridges, while the oldest rocks are located farther away. This age progression is consistent with the idea of seafloor spreading, where new crust is continuously formed at the ridges and moves away from the center.

4. Magnetic Reversals: The study of magnetic anomalies in the oceanic crust has revealed periods of magnetic reversal, where the Earth's magnetic field has flipped in the past. These magnetic reversals are recorded in the ocean floor rocks as bands of alternating magnetic orientations. The symmetrical pattern of magnetic anomalies on either side of mid-ocean ridges is evidence of the spreading of oceanic crust and the preservation of these magnetic records.

5. Earthquake and Volcanic Activity: Seismic activity, including earthquakes and volcanic eruptions, is concentrated along mid-ocean ridges, indicating the presence of tectonic activity and the upwelling of magma to form new oceanic crust.

By considering these lines of evidence together, scientists have developed the theory of sea-floor spreading, which forms an essential part of the broader theory of plate tectonics, explaining the movement of the Earth's lithospheric plates over geological time scales.

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An electromagnet is a type of magnet in which the magnetic field is produced by an electric current. It behaves exactly like a permanent magnet, like those magnets commonly used to stick items to our fridge.

To make a permanent magnet we need:

- One iron nail ( Could be fifteen centimeters (6 in) long )

- Three meters (10 ft) of copper wire

- One or more D-cell batteries

To make the electromagnet, we need to:

1. Wrap the Wire Around the Nail

2. Connect the Battery

And you are all set!

Answer:

We experience interference while listening to the radio. A radio station works by sending and receiving radio waves. Since the radio waves are being interfered with other waves which must have a wave nature.

The interference is the net result of two individual waves. It can be constructive or destructive interference and is the property of waves and not particles.

This interference is an example of electromagnetic radiation. Thus we experience wave behavior of electromagnetic radiation in our daily communications.

Answer: wave behavior

Explanation:

Answer:

Blue-green bacteria or cynobacteria belong to the kingdom Monera

Blue-green bacteria belongs to the kingdom

a. Monera.

Answer:

539 kPa

Explanation:

Pressure equals density times acceleration of gravity times depth.

P = ρgh

Water has a density of 1000 kg/m³, and acceleration of gravity is 9.8 m/s².

P = (1000 kg/m³) (9.8 m/s²) (55.0 m)

P = 539,000 Pa

P = 539 kPa