A 0.12-m-radius grinding wheel takes 5.5 s to speed up from 2.0 rad/s to 11.0 rad/s. What is the wheel's average angular acceleration?

As the board is raised by an angle θ, the block will be held in place by 3 forces:

• its weight, pointing downward (magnitude w )

• the normal force of the board pushing up on the block, pointing in the direction perpendicular to the board (mag. n)

• static friction, pointing in the direction parallel to the board, opposite the direction the block would slip (mag. f )

Decompose the vectors into components that are parallel and perpendicular to the board (taking the direction of n to be the positive direction perpendicular to the board, and the direction of f to be the negative directoin parallel to it), so that by Newton's second law, we have

• net parallel force:

∑ F = w (//) + f

∑ F = m g sin(θ) - µ n = 0

where µ = 0.45 is the coefficient of static friction, g = 9.80 m/s² is the mag. of the acceleration due to gravity, and m = 15.0 kg is the mass of the block.

• net perpendicular force:

∑ F = n + w (⟂)

∑ F = n - m g cos(θ) = 0

Solve for n in the equation for net perpendicular force:

n = m g cos(θ)

Substitute this into the equation for net parallel force:

m g sin(θ) - 0.45 m g cos(θ) = 0

Solve for θ :

sin(θ) - 0.45 cos(θ) = 0

sin(θ) = 0.45 cos(θ)

tan(θ) = 0.45

θ = tan⁻¹(0.45)

θ ≈ 24.2°

So the maximum angle the board can be lifted before the block starts to slide is about 24.2°, since the coefficient of static friction µ is such that

f = µ n

where f is the maximum magnitude of the static friction force.

Answer:he would most likely hit an element with which of the following characteristics: W) a naturally radioactive element X) a solid at room temperature Y) a gas at room temperature Z) a liquid at room temperature ANSWER: X) A SOLID AT ROOM TEMPERATURE

Explanation:

Given:

The length of the copper wire is: l = 2.84 m.

The diameter of the copper wire is: d = 0.04 m.

The resistivity of the copper is: ρ = 1.7 x 10^-8 Ωm.

To find:

The resistance of the copper wire.

Explanation:

The expression for the resistivity is given by:

Here, A is the cross-sectional area of the copper wire, which is given by:

Substituting the value in the above equation, we get:

Rearrange the resistivity expression as:

Substitute the values in the above equation, we get:

Final Answer:

The resistance of a copper wire is 0.038 milliOhms.

Answer:

reflect and absorb light

Explanation:

Opaque objects reflect some amount of light and absorb the rest. They do not transmit light.

Transparent objects transmit most light falling on them. They reflect a very small amount of light and absorb the rest.

Translucent objects undergo all three processes, i.e., they reflect, absorb and transmit the light that falls on them

Answer:

B. Why the expansion of the universe is accelerating

Explanation:

possibly pretty sure if not right then the answer is A. What dark matter is made of hope this helps please mark brainiest only answer plz

Why the expansion of the universe is accelerating is what scientists know

about the future of the universe.

Scientists have observed that radiation emitted by the galaxies have shifted

towards the red end of the electromagnetic spectrum. This means that there

has been an increase in the wavelength for this to occur.

This tells us that the universe is expanding which was why the wavelength

of the emission spectra experienced a shift or stretch.

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Answer:

NATURAL

Explanation:

well this is because a firefly isn't man- made it is a firefly it isn't a robot, it is an insect.

the input force by the output force 2. by adjusting the force's necessary application direction 3. 3N4. W=△E5.

Direction can refer to the way something moves, the way you must go to get somewhere, the way something is beginning to take shape, or the direction you are facing. When you turn right rather than left, that is an illustration of direction.

Your direction perception refers to your capacity to generally understand where you are or which course to go, even if you're in a strange environment. He quickly got lost due to his weak sense of direction. If you claim someone

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The electron number cannot be used instead because electrons can be removed from or added to an atom (option C)

The element of an atom is determined by its proton count, while the electron count can exhibit variability. Take, for instance, a sodium atom, which encompasses 11 protons and 11 electrons. However, it has the capacity to relinquish one electron, transforming into a sodium ion housing only 10 electrons.

This occurs due to the relatively loose binding of electrons to the nucleus, enabling their removal through the influence of an electric field or alternative mechanisms.

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On particle q1, there is a net force of about +25.6 N, directed to the right.

We must take into account the electrostatic forces between particle q1 and the other two particles, q2 and q3, in order to calculate the net force on particle q1. Coulomb's Law describes the electrostatic force between two charged particles:

F = k * |q₁ * q₂| / r²

F is the force, k is the electrostatic constant (9 x 109 N m2/C2), q1 and q2 are the charges' magnitudes, and r is the distance separating them.

Let's first determine the force between q1 and q2:

F₁₂ = k * |q₁ * q₂| / r₁₂²

F₁₂ = (9 x 10^9 N m²/C²) * |(-29.6 μC) * (+37.7 μC)| / (0.630 m)²

F₁₂ = (9 x 10^9 N m²/C²) * (29.6 x 10^-6 C) * (37.7 x 10^-6 C) / (0.630 m)²

F₁₂ ≈ -7.45 N

The minus symbol denotes an attracting force between q1 and q2, pointing to the left.

Let's next determine the force between q2 and q3:

F₂₃ = k * |q₂ * q₃| / r₂₃²

F₂₃ = (9 x 10^9 N m²/C²) * |(+37.7 μC) * (-10.8 μC)| / (0.315 m)²

F₂₃ = (9 x 10^9 N m²/C²) * (37.7 x 10^-6 C) * (10.8 x 10^-6 C) / (0.315 m)²

F₂₃ ≈ +33.05 N

Positively directed to the right, the force between q2 and q3 is shown by the positive sign.

We must now add all the forces in order to determine the net force on q1:

Net force = F₁₂ + F₂₃

Net force ≈ -7.45 N + 33.05 N

Net force ≈ +25.6 N

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The force required to rescue in the swimming pool with a mass of 60 kg is 588N and the pressure exerted in the area of 0.5 m² is 1.176×10³Pa.

Force is defined as the push or pull of an object. Force equals the product of the mass and acceleration of the object. Acceleration is defined as the rate of change of velocity per unit time. The force also equals the rate of change of momentum per unit of time. The unit of force is Newton (N).

Pressure is defined as the force applied perpendicular to the surface area. It equals the ratio of force per unit area and the unit of pressure is Pascal (Pa).

From the given,

mass of the swimmer's body (m) = 60 kg

Acceleration. due to gravity (g) = 9.8m/s²

area (A) = 0.5 m²

Force, F = m×a

F = 60×9.8

  = 588 N

The force to rescue the swimmer's body is 588N.

Pressure  = Force/Area

               = 588 / 0.5

               = 1176 Pa

               = 1.176×10³Pa

The pressure exerted on the body is 1.176×10³Pa.

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ANSWER AND EXPLAINATION:
To calculate the impulse imparted on the baseball, we can use the impulse-momentum principle, which states that the impulse experienced by an object is equal to the change in momentum of the object. Mathematically, it can be expressed as:

Impulse = Change in momentum

The momentum of an object is given by the product of its mass and velocity:

Momentum = mass × velocity

In this case, the baseball has an initial mass of 0.14 kg and an initial velocity of 32 m/s. After being struck by the bat, it travels in the opposite direction at a velocity of 49 m/s.

Therefore, the change in momentum is given by:

Change in momentum = (mass × final velocity) - (mass × initial velocity)

Change in momentum = mass × (final velocity - initial velocity)

Change in momentum = 0.14 kg × (49 m/s - (-32 m/s))

Change in momentum = 0.14 kg × (49 m/s + 32 m/s)

Change in momentum = 0.14 kg × 81 m/s

Change in momentum = 11.34 kg·m/s

So, the impulse imparted on the baseball is 11.34 kg·m/s.

Answer: B

Explanation: B is the correct statement describing the positions of the Moon, the Sun, and the Earth during a new moon. The Moon is between Earth and the Sun.

During a new moon, the Moon is positioned between the Sun and the Earth, with the illuminated side of the Moon facing away from the Earth. This means that the side of the Moon that faces the Earth is not receiving any sunlight, making it invisible to us from Earth. The new moon is the first phase of the lunar cycle and occurs roughly every 29.5 days.

The inverse of the mass is referred to as acceleration. The acceleration will be slower the more mass there is.

Acceleration is the rate of change in an object's velocity over time in mechanics. One of the vector quantities is speed. The direction of the net force exerted on an object is what determines its acceleration. The change in velocity rate is referred to as acceleration. Usually, but not always, acceleration implies a change in velocity.

A circular object moving at a constant velocity is still accelerating because its velocity is changing in the opposite direction. In physics, acceleration is the rate of change in an object's velocity over time.  According to Newton's second law, the sum of all forces acting on an object determines its acceleration. Meters per second (ms²) is the SI unit for acceleration.

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The experiment to show the random motion of the particles is the movement of particles in a solution is the simplest representation of motion of particles.

Pick up two glass beakers. Fill one beaker with hot water and the second one with cold water. Add KMnO4 crystals in very small quantities to both. We thus see that KMnO4 particles move faster in hot water than in cold water.

Pick up some iron and  a piece of chalk. We learn that it's quite difficult to work with iron. This leads us to believe that the Forces can affect matter particles. among them. The pressure kept between  particles and the power of the attraction in materials is at its strongest between particles the least in gases.

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Based on the information, it should be noted that the resistance R is 0.5 Ω.

When S1 and S2 are open, i leads e by 30°. In this case, the circuit consists of only the inductor (L) and the capacitor (C) in series. Therefore, the impedance of the circuit can be written as:

Z = jωL - 1/(jωC)

Since i leads e by 30°, we can express the phasor relationship as:

I = k * e^(j(ωt + θ))

Z = jωL - 1/(jωC) = j(120π)L - 1/(j(120π)C)

Re(Z) = 0

By equating the real parts, we get:

0 = 0 - 1/(120πC)

Let's assume that there is a resistance (R) in series with the inductor and capacitor. The impedance equation becomes:

Z = R + jωL - 1/(jωC)

Z = R + jωL

Im(Z) = ωL > 0

Substituting the angular frequency and rearranging the inequality, we have:

120πL > 0

L > 0

This condition implies that the inductance L must be greater than zero.

When S1 and S2 are closed, i has an amplitude of 0.5 A. In this case, the impedance is:

Z = R + jωL - 1/(jωC)

Since the amplitude of i is given as 0.5 A, we can express the phasor relationship as:

I = 0.5 * e^(j(ωt + θ))

By substituting this phasor relationship into the impedance equation, we can determine the value of R. The real part of the impedance must be equal to R:

Re(Z) = R

Since the amplitude of i is 0.5 A, the real part of the impedance must be equal to 0.5 A: 0.5 = R

Therefore, the resistance R is 0.5 Ω.

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Answer:

I had to put the blocks on the weigher, and write down how much they weigh. I had to put the blocks next to the ruler to measure the height.

Explanation:

u would change wright to write because wright can be a name and if u change it to write that would be correct because u are actually writing something down. so it would be right because u are writing something down

The work-energy theorem states that the change in the kinetic energy of an object will be equal to the net work done on the object.

Mathematically, it can be expressed as;

ΔKE = W

Where; ΔKE represents the change in kinetic energy of the object,

W represents the net work done on the object.

This theorem states that when work is done on an object, it results in a change in its kinetic energy. If work is done on an object, its kinetic energy increases, and if work is done by an object, its kinetic energy decreases.

This theorem is a fundamental principle in physics that relates the concepts of work and energy, and it is often used to analyze the motion and behavior of objects in various physical systems.

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The approximate heat transfer through 1.65 cm of air with a temperature difference of 23.0 °C is approximately 24.4 J/s.

To approximate the heat transfer through the air layer in the double-paned window, we can assume that the glass layers have a negligible impact on the heat flow. The heat transfer can be calculated using Fourier's Law of Heat Conduction, which states that the heat flow (Q) is proportional to the temperature difference (ΔT) and inversely proportional to the thickness (L) and thermal conductivity (k) of the material.

First, we need to calculate the effective thermal conductivity of the air layer due to its thickness and the thermal conductivity ratio between air and glass. Let's denote the thermal conductivity of air as k_air and the thermal conductivity of glass as k_glass. Since glass has a thermal conductivity roughly 36 times greater than air, we have k_glass = 36 * k_air.

Next, we calculate the effective thermal conductivity of the air layer as:

k_eff = (k_air * L_air) / (L_air + k_glass)

Substituting the given values, we have:

k_eff = (k_air * 0.0165 m) / (0.0165 m + 0.005 m) = 0.01309 * k_air

Now, we can calculate the heat flow per second through the air layer using the formula:

Q = (k_eff * A * ΔT) / L_air

Substituting the given values, we get:

Q = (0.01309 * k_air * 0.760 m^2 * 23.0 K) / 0.0165 m = 24.4 J/s

Therefore, the approximate heat transfer through 1.65 cm of air with a temperature difference of 23.0 °C is approximately 24.4 J/s.

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Answer:

For eintein's frame of reference, both beam travel at the same speed.

For my own frame of reference, both beams travel at the same speed.

Explanation:

According to special relativity, the speed of light is the same in all direction on all reference frame. If not for this law we will assume the from beam will have a relative speed that will be the speed of light plus the speed of the fright car. This is not so and it violates the speed limit of light which according to the first law is the highest speed possible and nothing can go beyond that.

Answer:

(1.8 × 10^9) meters in one minute

Explanation:

To determine how far light can travel in one minute, we need to multiply its speed by the number of seconds in a minute.

The speed of light is 3 × 10^8 meters per second.

There are 60 seconds in a minute.

Therefore, the distance light can travel in one minute is:

Distance = Speed × Time

Distance = (3 × 10^8 meters per second) × (60 seconds)

Calculating this, we get:

Distance = 3 × 10^8 meters/second × 60 seconds

Distance = 18 × 10^8 meters

Distance = 1.8 × 10^9 meters

So, light can travel approximately 1.8 billion (1.8 × 10^9) meters in one minute.

The current I through the 4 kΩ resistor in the original circuit is 0.199 mA.

Thévenin's theorem states that any linear network of voltage and current sources and resistors can be replaced by an equivalent circuit consisting of a single voltage source and a single resistor. The equivalent circuit provides the same output voltage and current as the original circuit for any external load connected to it.

To find the current I in the circuit using Thévenin's theorem, we need to follow these steps:

Step 1: Find the Thévenin equivalent voltage (Vth) across the 4 kΩ resistor.

To find Vth, we need to first find the open circuit voltage (Voc) across the 4 kΩ resistor. We can do this by removing the 4 kΩ resistor and finding the voltage between its two terminals using a voltage divider:

Voc = 6 kΩ/(2 kΩ + 6 kΩ) x 2 mA = 1.2 V

Next, we need to find the Thévenin equivalent resistance (Rth) across the 4 kΩ resistor. To do this, we need to short-circuit all the independent voltage sources (in this case, there is only one) and find the equivalent resistance seen from the terminals of the 4 kΩ resistor. With the 2 mA current source shorted out, the 2 kΩ and 4 kΩ resistors are in parallel:

Rth = 2 kΩ || 4 kΩ = 1.33 kΩ

Step 2: Replace the original circuit with the Thévenin equivalent circuit.

We can now replace the original circuit with the Thévenin equivalent circuit, which consists of a voltage source Vth = 1.2 V in series with a resistor Rth = 1.33 kΩ.

Step 3: Find the current I through the 4 kΩ resistor in the Thévenin equivalent circuit.

To find the current I, we can use Ohm's law:

I = Vth/(Rth + 4 kΩ) = 1.2 V/(1.33 kΩ + 4 kΩ) = 0.199 mA

Therefore, the current I through the 4 kΩ resistor in the original circuit is 0.199 mA.

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The energy lost to friction and air resistance is 186 J.

option B.

The energy lost to friction and air resistance is calculated from the change in the mechanical energy of the pendulum.

The initial potential energy of the pendulum at the initial position is calculated as;

PEi = mghi

where;

P.Ei = 12 kg x 9.8 m/s² x 20 m

P.Ei = 2,352 J

The final kinetic energy of the pendulum is calculated as follows;

K.Ef = 0.5 x 12 kg x (19 m/s)²

K.Ef = 2,166 J

ΔE = 2,166 J - 2,352 J

ΔE = -186 J

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Answer: The football spent 3.6 s in air

Explanation: I know im correct :-)

Answer-

mk thats kool.

Answer:

Force Friction

Explanation:

If you wanted to measure the composition and magnetism of a star, then the best way to do so is : spectroscopy :

The common method astronomers use to determine the composition of stars and planets is spectroscopy. Each element absorbs light at specific wavelengths unique to that atom and when astronomers look at object's spectrum, they can determine its composition based on wavelengths.

Spectrometers are used in astronomy to analyze the chemical composition of stars and planets, and gather data on the origin of the universe. The science of spectroscopy is sophisticated. From spectral lines astronomers can determine not only the element, but also temperature and density of that element in the star.

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IMA of the pulley system is 3.

The length of the effort arm of a lever divided by the length of the resistance arm represents the ideal mechanical advantage, IMA.

IMA = Resistance force/Effort force

IMA = Fr/Fe

Calculating IMA involves measuring the number of ropes present in the pulley system.

Therefore, IMA = 3

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Answer:

735 N

Explanation:

If a woman has mass 75kg and u know that mass is constant everywhere then just apply the formula W=mg...as gravity on earth is 9.8 m/s2 , so her weight will be 735 N...hope it helps...

If a woman has a mass of 75 kilograms then her weight on the earth would be 735.75 Newtons, because the weight of the woman is the multiplication of the mass of the woman and the acceleration due to the gravity of the earth.

It can be defined as the force by which a body attracts another body toward its center as the result of the gravitational pull of one body and another,

As given in the problem if a woman has a mass of 75 kilograms we have to find the weight of the woman,

The weight of the woman = mass of the woman × acceleration due to the gravity of the earth

                                           = 75 kilograms × 9.81

                                           =735.75 Newtons

Thus, the weight of a woman who has a mass of 75 kilograms would be 735.75 Newtons

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Answer:

57.0 m

Explanation:

Assume the time it takes for the sound to reach the top of the well is negligible.

Given:

v₀ = 0 m/s

a = 9.8 m/s²

t = 3.41 s

Find: Δy

Δy = v₀ t + ½ at²

Δy = (0 m/s) (3.41 s) + ½ (9.8 m/s²) (3.41 s)²

Δy = 57.0 m

Answer:

57 m

Explanation:

The magnitude of the electric flux through the sheet is 4.05 N m² C⁻¹ (Option E).

The electric flux through a surface is given by the product of the electric field strength and the area of the surface projected perpendicular to the electric field.

In this case, the electric field strength is 18 N C⁻¹, and the area of the sheet projected perpendicular to the electric field is 0.450 m²

(since the normal to the sheet makes an angle of 60° with the electric field). Multiplying these values gives the electric flux:

Electric flux = Electric field strength × Area

Electric flux = 18 N C⁻¹ × 0.450 m²

Electric flux = 8.1 N m² C⁻¹

In summary, the magnitude of the electric flux through the sheet is 4.05 N m² C⁻¹. This value is obtained by multiplying the given electric field strength by the projected area of the sheet perpendicular to the electric field.

The angle of 60° is taken into account to determine the effective area for calculating the flux.(Option E).

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