A fan blade rotates with angular velocity given by ωz(t)= γ − β t2, where γ = 4.90 rad/s and β = 0.750 rad/s3 . part a calculate the angular acceleration as a function of time.

The energy required to heat a fixed mass of an ideal gas from 50 to 80℃ is the same at both 1 atm and 3 atm, as it depends on the gas's heat capacity and the temperature change, not pressure.

The energy required to heat a fixed mass of an ideal gas from 50 to 80℃ would be the same for both cases of constant pressure at 1 atm and 3 atm. The reason behind this is that the amount of energy required to raise the temperature of an ideal gas is dependent on its heat capacity and the change in temperature, not the pressure at which it is heated. In both cases (a) and (b), the change in temperature is the same, so the energy required will also be the same.

The potential energy change of a spring with a spring constant of 95 N/m compressed by 0.45 m is approximately 9.62 J, calculated using the formula U = 1/2 kx².

When a spring with a spring constant of 95 N/m is compressed a distance of 0.45 m from its relaxed position, the potential energy of the spring changes according to the formula for elastic potential energy, U = 1/2 kx², where 'k' is the spring constant and 'x' is the distance of compression or extension from the equilibrium position. In this case, the spring's potential energy change is calculated as U = 1/2 × 95 N/m × (0.45 m)².

By computing this, U = 1/2 × 95 × 0.45² = 0.5 × 95 × 0.2025 J. This results in U = 9.61875 J, so the potential energy of the spring changes by approximately 9.62 J.

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Answer:

shelf a is increase shelf b is stay the same and shelf c is decrease

Explanation:

i did it on edu

The work function of the cathode is found to be 0.10 eV, calculated by using the relationship between the maximum kinetic energy of photoelectrons, the photon energy, and the work function within the context of the photoelectric effect.

The question involves finding the work function of a cathode in a photoelectric effect scenario. We know that the maximum kinetic energy (KE) of photoelectrons is related to the photon energy (hf) and the work function (
W) as KE = hf - W. We were given that the kinetic energy decreased to 1.50 eV when the wavelength increased by 50%, which implies the initial wavelength corresponds to a photon energy that gives photoelectrons a kinetic energy of 3.10 eV. Let's express these energies in the equation form:

KE1 = hf1 - W, where KE1 = 3.10 eV

KE2 = hf2 - W, where KE2 = 1.50 eV and hf2 = hf1/1.5 (since the wavelength increased by 50%, energy decreases by the same factor)

By subtracting the second equation from the first, we eliminate W and can solve for hf1. Once we have hf1, we can solve for the work function using either of the equations:

3.10 eV - 1.50 eV = hf1 - hf1/1.5

1.60 eV = 0.5 * hf1

hf1 = 3.20 eV

Work function W = hf1 - KE1 = 3.20 eV - 3.10 eV = 0.10 eV

The work function of the cathode is therefore 0.10 eV.

Final answer:

The second law of thermodynamics states that in any energy transfer, some high-quality energy is always degraded, leading to increased disorder or entropy in the system.

Explanation:

The second law of thermodynamics dictates that some high-quality energy is always degraded to a lower quality form during energy transfers. This law further implies that no energy transfer is completely efficient, thus resulting in an increase in entropy, or disorder, within a system. This is a fundamental concept in physics that puts an arrow on the transformations of matter and energy, signifying a one-way flow from usable to less-usable forms of energy. It is most commonly observed through heat loss, where energy spontaneously transfers from a hotter object to a cooler one, increasing the disorder of the system.

Using TMS permits scientists to temporarily enhance or depress activity in a specific area of the brain.

Transcranial magnetic stimulation (TMS) is a noninvasive procedure that uses magnetic fields to stimulate nerve cells in the brain to improve symptoms of depression. TMS is typically used when other depression treatments haven't been effective.

The electromagnet painlessly delivers a magnetic pulse that stimulates nerve cells in the region of your brain involved in mood control and depression. It's thought to activate regions of the brain that have decreased activity in depression.

a single Transcranial magnetic stimulation (TMS) pulse can cause disruption in the contralateral hand muscles for ∼200 ms. These different temporal windows of disruption across different brain regions

Transcranial magnetic stimulation targets the activity of nerve cells in your brain, which may alleviate depression symptoms. It could also have benefit for disorders like OCD, anxiety, and PTSD as well.

hence , correct option is  A. TMS (Transcranial magnetic stimulation)

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Answer: Option (a) is the correct answer.

Explanation:

Elements of group 17 are known as halogens whereas elements of group 18 are known as noble gases.

Noble gases have completely filled valence shell. Therefore, they are stable and does not react easily.

Whereas halogens have incompletely filled sub-shells, therefore, in order to gain stability they react readily with another atom.

Halogen atoms are also electronegative in nature. On moving down the group, the electronegativity decreases. Thus, the atom at the top of group 17, that is, fluorine is the most reactive non-metal because fluorine has high electronegativity so, it readily attracts an electron in order to completely fill its sub-shell.

Thus, we can conclude that at the top of group 17 most reactive nonmetal elements are found on the periodic table.

Answer: A

Explanation: 100 on edge

To calculate the final pressure of a gas after cooling, the combined gas law is used. The final pressure of the gas cooled from 72.3 0C to 40.1 0C in a constant volume is calculated to be 0.896 atm.

The student is asking to calculate the final pressure of an ideal gas after it is cooled from 72.3 0C to 40.1 0C without changing its volume. To find the final pressure, you can use the combined gas law, which relates the pressure, volume, and temperature of a gas. The combined gas law is P1/T1 = P2/T2, where P1 and T1 are the initial pressure and temperature, and P2 and T2 are the final pressure and temperature. Given that the initial pressure (P1) is 0.989 atm and the initial temperature (T1) is 345.45 K (72.3 0C + 273.15), and the final temperature (T2) is 313.25 K (40.1 0C + 273.15), and the volume remains constant, we can solve for the final pressure (P2).

Initial pressure (P1): 0.989 atm
Initial temperature (T1): 345.45 K
Final temperature (T2): 313.25 K
Final pressure (P2): ?
To solve for P2, we rearrange the combined gas law to P2 = P1 imes (T2 / T1):

P2 = 0.989 atm imes (313.25 K / 345.45 K)

P2 = 0.989 atm imes 0.906 = 0.896 atm (rounded to three significant digits)

Therefore, the final pressure of the gas would be 0.896 atm after it is cooled to 40.1 0C.

Science is a systematic process, which means it follows a careful method that involves observation and experimentation. Through experimentation, information is collected that supports or refutes a scientist’s hypothesis.

edginuity answer

Answer:

Acceleration, [tex]a=k\dfrac{v^2}{r}[/tex]

Explanation:

It is given that, the acceleration a of a particle moving with uniform speed v in a circle of radius r is proportional to some power of r and some power of v. Mathematically, it can be written as :

[tex]a\propto r^nv^m[/tex]

or

[tex]a=r^nv^m[/tex]...........(1)

Dimensional formula of a = [tex][LT^{-2}][/tex]

Dimensional formula of r = [tex][L][/tex]

Dimensional formula of v = [tex][LT^{-1}][/tex]

Using dimensional analysis in equation (1) as :

[tex][LT^{-2}]=[L]^n[LT^{-1}]^m[/tex]

[tex][LT^{-2}]=[L]^{n+m}[T^{-m}][/tex]

Equation both sides of equation as :

n + m = 1,  m = 2

This gives, n = -1

Use the value of m and n in equation (1) in order to get the formula :

[tex]a=kr^{-1}v^2[/tex]

[tex]a=k\dfrac{v^2}{r}[/tex]

Hence, this is the required solution.

infrared is heat so thermogram will allow u to see it

Answer:

thermogram

Explanation:

A policeman's whistle has a _____.

high pitch

Answer:

Electrical Resistivity

Explanation:

As we know that all different type of conductors has its different unique resistivity due to which all conductors will show different resistance for same shape and size.

As we know that the resistance of a conductor is given as

[tex]R = \rho\frac{L}{A}[/tex]

here we know

[tex]\rho[/tex] = resistivity

L = length of conductor

A = crossectional area of conductor

so here for all conductors the resistivity is unique property due to which all will show different resistance

A 2.03 kg book is placed on a flat desk, with a coefficient of static friction between the book and the desk of 0.522 and a coefficient of kinetic friction of 0.283, requires a force of 10.4 N to start moving.

First, we have to calculate the Normal force (N), which, in a flat horizontal desk, has the same magnitude and opposite sense as the weight of the object (W). We can calculate its magnitude using the following expression.

[tex]|N| = |W| = m \times g = 2.03 kg \times \frac{9.81m}{s^{2} } = 19.9 N[/tex]

where,

To begin moving the book, we must overcome the highest static friction force (F), which can be calculated using the following expression.

[tex]F = \mu \times N = 0.522 \times 19.9 N = 10.4 N[/tex]

where,

A 2.03 kg book is placed on a flat desk, with a coefficient of static friction between the book and the desk of 0.522 and a coefficient of kinetic friction of 0.283, requires a force of 10.4 N to start moving.

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Electrons with 12.8 eV energy can excite hydrogen atoms to several higher energy levels without ionizing them. Upon de-excitation, these atoms can emit a series of photons, each with a unique energy corresponding to the energy differences between these levels. Therefore, a variety of different photon energies could be observed, each corresponding to specific transitions between the energy levels.

When electrons of energy 12.8 eV are incident on hydrogen atoms in their ground state, the electrons can be excited to higher energy levels. To determine how many different photon energies can be observed, we must consider the energy levels that 12.8 eV can reach from the ground state. The ground state of hydrogen is -13.6 eV. An electron in this state can be excited to energy levels such as -3.4 eV (second energy level), -1.51 eV (third energy level), and -0.85 eV (fourth energy level), and so on, as long as the energy is less than 12.8 eV. However, an important point to note is that the energy required to excite an electron must match the energy difference between these levels precisely. Upon returning to the ground state or another lower energy state, these electrons will emit photons with energies corresponding to the differences in energies between these levels.

Whichever ball is placed higher has the greatest speed at the moment of impact. Speed may be described as the distance an item goes in the amount of time.

The distance that an item travels in relation to the length of time it takes to do so may be used to define speed. In other terms, it is a determination of an object's motion's speed without direction Velocities are what we get when speed and direction are combined.

Speed may be described as the distance an item goes in the amount of time it needs to do so. To put it in another way, it is an estimate of how swiftly something travels. Speed is measured in metres per second, or m/s, since the distance is measured in meters and the time is measured in seconds. Whichever ball is placed higher has the greatest speed at the moment of impact.

Therefore, whichever ball is placed higher has the greatest speed at the moment of impact.

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A forklift raises a 1,020 N crate 3.50 m up to a shelf. How much work is done by the forklift on the crate?

The forklift does  

⇒ 3,570 J of work on the crate. the answer is 3570

Answer : Work done on the crate is 3570 J

Explanation :

Force acting on forklift due to its mass is 1020 N

Distance covered in lifting it, d = 3.5 m

Mathematically, the work done is defined as :

[tex]W=F\times d[/tex]

So, [tex]W=1020\ N\times 3.5\ m[/tex]

[tex]W=3570\ J[/tex]

The forklift does 3570 J work on the crate.      

Hence, this is the required solution.                      

Answer

0.45 moles of silver chloride will be produced

Explanation

The mole ratios for the reactions are 1 for all reactants and reactants. This means that 1 mol of potassium chloride will react with 1 mol of  silver fluoride to produce 1 mol of silver chloride and 1 mol of potassium fluoride.

If only 0.45 mol of potassium chloride is available to react with 0.9 mol of silver fluoride, the potassium chloride will be the limiting reagent in this reaction. This means that only 0.45 mol of each of the product will be formed. This means that only 0.45 mol of silver chloride will be formed.

.

Answer:

Pitch decreases

Explanation:

The number of oscillation or number of vibration per unit time is called the frequency of a sound wave. The frequency of sound wave is also called the pitch of the wave. It is denoted by f or [tex]\nu[/tex]. Its SI unit is hertz or Hz.

The speed of the sound wave is given by :

[tex]v=\nu\times \lambda[/tex]

It is clear form the above expression that the pitch of the sound wave is inversely proportional to the wavelength.

So, when the wavelength of a sound wave increases its pitch decreases.

Answer:

  27.9 m/s

Explanation:

You want the speed of a 60 kg skier at the bottom of a 50 m high slope if 6 kJ of energy is lost to friction.

The potential energy of the skier at the top of the slope is ...

  PE = mgh

  PE = (60 kg)(9.8 m/s²)(50 m)

The kinetic energy of the skier at the bottom of the slope is this potential energy, less the energy lost due to friction.

  KE = PE -6000 J

That is related to the skier's speed by ...

  KE = 1/2mv²

So, the speed is ...

  [tex]v^2=\dfrac{2\cdot KE}{m}=\dfrac{2(mgh-6000)}{m}=2\left(gh-\dfrac{6000}{m}\right)\\\\\\v^2=2\left(9.8\cdot50-\dfrac{6000}{60}\right)=780\\\\\\v=\sqrt{780}\approx27.9\quad\text{m/s}[/tex]

The speed of the skier at the bottom of the slope is about 27.9 m/s.

2,317 meters on edg!!