A postal service worker lifts a package into a truck. She exerts 22 J of work lifting the package for 4 seconds. How much power did she user

Answers

Answer 1
Given:-

Work done = 22 Joules

Time taken = 4 Seconds

To be calculated:-

Calculate the power .

Formula used:-

Power = Work done/Time taken

Solution:-

We know that,

[tex] \sf{Power = \dfrac{Work \: done}{Time \: taken } }[/tex]

★ Putting the values in the above formula,we get:

[tex] \sf{Power = \dfrac{22}{4} }[/tex]

[tex] \sf{Power = 5.5 \: watts}[/tex]


Related Questions

Two gratings A and B have slit separations dA and dB, respectively. They are used with the same light and the same observation screen. When grating A is replaced with grating B, it is observed that the first-order maximum of A is exactly replaced by the second-order maximum of B. (a) Determine the ratio dB/dA (No units) of the spacings between the slits of the gratings. Then find the next two principla maxima of grating A and the principal maxima of B that exactly replace them when the gratings are switched [(b) and (c) for the first pair, (d) and (e) for the second pair]. Identify these maxima by their order numbers (No units), listing the maxima for grating B first.

Answers

Answer:

a) dB / dA = 2 ,

b) Network B     Network A

        2                         1

        4                         2

        6                         3

Explanation:

a) The expression for grating diffraction is

         d sin θ = m λ

where d the distance between two slits, λ the wavelength and m an integer that represents the diffraction range

In this exercise we are told that the two spectra are in the same position, let's write the expression for each network

Network A

m = 1

         sin θ = 1 λ / dA

Network B

m = 2

        sin θ = 2 λ / dB

they ask us for the relationship between the distances, we match the equations

            λ / dA) = 2 λ / dB

            dB / dA = 2

         

b) let's write the equation of the networks

         sin θ = m_A  λ / dA

         sin θ = m_B  λ / dB

we equalize

           m_A  λ/ dA = m_B  λ / dB

we use that

          dB / dA = 2

           m_A 2 = m_B

therefore the overlapping orders are

Network B     Network A

   2                         1

   4                         2

    6                       3

The location of a particle is measured with an uncertainty of 0.13 nm. One tries to simultaneously measure the velocity of this particle. What is the minimum uncertainty in the velocity measurement. The mass of the particle is 1.745×10-27 kg

Answers

Answer:

The minimum uncertainty in the velocity is 232.57 m/s.

Explanation:

Given that,

Location of a particle with uncertainty = 0.13 nm

Mass of particle [tex]m=1,745\times10^{-27}\ kg[/tex]

We need  to calculate the minimum uncertainty in the velocity

Using heisenberg's uncertainty principle,

[tex]\Delta x\cdot \Delta p\geq \dfrac{h}{4\pi}[/tex]

[tex]\Delta x\cdot m\Delta v \geq \dfrac{h}{4\pi}[/tex]

[tex]\Delta v=\dfrac{h}{4\pi\times m\Delta x}[/tex]

Put the value into the formula

[tex]\Delta v=\dfrac{6.63\times10^{-34}}{4\pi\times 1.745\times10^{-27}\times0.13\times10^{-9}}[/tex]

[tex]\Delta v= 232.57\ m/s[/tex]

Hence, The minimum uncertainty in the velocity is 232.57 m/s.

The longest pipe found in most medium-size pipe organs is 2.40 m (7.87 ft) long. What is the frequency of the note corresponding to the fundamental mode if the pipe is open at one end and closed at the other

Answers

Answer:

34.3Hz

Explanation:

We know that

For a pipe open at one end, fundamental frequency (Fo)

is

Fo = v/4L

Where v= 340m/s

Fo = 340/4 x 2.48 = 34.3Hz

An electric heater supplies 5kw of power to atank of water assume all the energy supplied is converted into heat energy and the energy losses to the surrounding are negligible how long will it take to heat 500 kg of water in the tank from 25c to 100c specifiv heat capacity water 4200j/kgc​

Answers

Answer:

8hours 45minutes

Explanation:

Amount of heat energy used up by the electric substance = heat gained by the water.

Amount of heat energy used up by the electric substance = Power * Time

heat gained by the water. = mcΔt

m is the mass of the water in kg

c is the specific heat capacity

Δt is the change in temperature

Given parameters

Power = 5kW = 5000W

mass of water m = 500kg

c = 4200J/kgC

Δt = 100°C - 25°C = 75°C

Required

Time taken

Substituting the given parameters into the formula

Pt = mcΔt

5000t = 500*4200*75

5000t = 157,500,000

Divide both sides by 5000

t =  157,500,000/5000

t = 31,500 secs

t = (31,500/3600)hrs

t = 8.75hours

t = 8hours 45minutes

Hence it takes 8hours 45minutes to heat 500 kg of water in the tank from 25c to 100c

Select all of the answers that can serve as a meaning for sexuality. (more than one answer may be selected)
gender
sexual identity
self esteem
sexual relationships

Answers

gender and self esteem is the answer

What is the radius of a tightly wound solenoid of circular cross-section that has 180 turns if a change in its internal magnetic field of 3.0 T/s causes a 6.0 A current to flow? The resistance of the circuit that contains the solenoid is 17 Ω. The only emf source for the circuit is the induced emf. A. 0.54 m B. 0.043 m C. 0.25 m D. 0.014 m

Answers

Answer:

C. 0.25 m

Explanation:

Given;

current flow in the solenoid, I = 6.0 A

number of turns of the solenoid, N = 180 turns

the resistance of the circuit, R = 17 Ω

change in the magnetic field, dB/dt = 3.0 T/s

The emf of the circuit is given by;

V = IR

V = 6 x 17

V = 102 Volts

Magnitude of induced emf is given by;

[tex]E = N(\frac{dB}{dt} )A[/tex]

Where;

A is area of the solenoid

[tex]E = N(\frac{dB}{dt} )A\\\\A = \frac{E}{N(\frac{dB}{dt} )} \\\\A = \frac{102}{180 *3} \\\\A = 0.18889 \ m^2[/tex]

Area of the circular solenoid is given by;

A = πr²

where;

r is radius of the solenoid

[tex]r = \sqrt{\frac{A}{\pi} }\\\\r = \sqrt{\frac{0.18889}{\pi} }\\\\r = 0.25 \ m[/tex]

Therefore, the correct option is C. 0.25 m

You are standing on a train station platform as a train goes by close to you. As the train approaches, you hear the whistle sound at a frequency of f1 = 94 Hz. As the train recedes, you hear the whistle sound at a frequency of f2 = 71 Hz. Take the speed of sound in air to be v = 340 m/s.
Part (a). Find an equation for the speed of the sound source. (In this case, it is the speed of the train.)
Part (b). Find the numeric value, in meters per second, for the speed of the train.
Part (c). Find an equation for the frequency of the train whistle that you would hear if the train were not moving.
Part (d). Find the numeric value, in hertz, for the frequency of the train whistle that you would hear if the train were not moving.

Answers

Answer:

Kindly check explanation

Explanation:

Given the following :

As train approaches ; frequency, f1 = 94Hz

As train recedes; frequency, f2 = 71Hz

Speed of sound in air ; v = 340m/s

A) speed of sound source (speed of train) = vs

From doppler effect :

As the train recedes ;

f2 = fs [v / (v + vs)] - - - - (1)

As train approaches :

f1 = fs [v / (v - vs)] ----- (2)

To find vs equate (1) and (2)

fs [v / (v - vs)] = fs [v / (v + vs)]

f1/f2 = v / (v - vs) ÷ v / (v + vs)

f1 / f2 = v / (v - vs) × (v + vs) / v

f1 / f2 = (v + vs) / (v - vs)

Let f1 / f2 = f

f = (v + vs) / (v - vs)

f (v - vs) = v + vs

fv - fvs = v + vs

fv - v = vs + fvs

v(f - 1) = vs(1 + f)

v(f - 1) / (1 + f) = vs

B)

v(f - 1) / (1 + f) = vs

f = f1 / f2 = 94/71 = 1.32 Hz

340(1.324 - 1) / (1 + 1.324) = vs

vs = 340(0.324) / 2.324

vs = 110.16 / 2.324

vs = 47.40 m/s

C.) To calculate fs, frequency of train, substitute vs into our equation.

f2 = fs [v / (v + vs)]

Following our substitikn we obtain:

fs = (2f / (f + 1))f2

D)

fs = (2f / (f + 1))f2

fs = 2(1.324) / (1.324 +1)) × 71

fs = (2.648 / 2.324) × 71

fs = 1.1394148 × 71

fs = 80.898450

fs = 80.90 Hz

Two capacitors, C 1 and C 2, are connected in series across a source of potential difference. With the potential source still connected, a dielectric is now inserted between the plates of capacitor C 1. What happens to the charge on capacitor C 2

Answers

Answer:

Q2 will increase

Explanation:

The charge increases because a dielectric increases capacitance by a factor of K fromthe relation

C= KEoA/d

And since C1=C2

And Capacitance varies directly to charge in Q= CV

Then Q2 will increase

if V has a magnitude of 14 units and the same direction qs a vector 3i+6j+2k find v​

Answers

Answer:

v = 6i + 12j + 4k

Explanation:

Find the magnitude of the direction vector.

√(3² + 6² + 2²) = 7

Normalize the direction vector.

3/7 i + 6/7 j + 2/7 k

Multiply by the magnitude of v.

v = 14 (3/7 i + 6/7 j + 2/7 k)

v = 6i + 12j + 4k

The vector  [tex]\overrightarrow V[/tex] = 6i + 12j + 4k

We have a vector [tex]\overrightarrow V[/tex] whose magnitude is 14 units and its direction is same as that of vector [tex]\overrightarrow A[/tex]= 3i + 6j + 2k.

We have to find the vector [tex]\overrightarrow V[/tex].

If two vectors have same direction than what is the relation between their unit vectors?

If two vectors have the same direction, this means that they are parallel and hence have the same unit vectors.

According to the question, we have vector -

A  = 3i + 6j + 2k.

The magnitude of vector A will be -

|A| = [tex]\sqrt{(3)^{2} +(6)^{2} +(2)^{2} }[/tex] = [tex]\sqrt{49}[/tex] = 7

We know the following relation -

[tex]\overrightarrow A = |A|a_{u}[/tex]  , where [tex]a_{u}[/tex] is the unit vector along the vector A.

[tex]a_{u}[/tex] = [tex]\frac{\overrightarrow A}{|A|}[/tex] = [tex]\frac{1}{7} (3i + 6j + 2k)[/tex]

Now, we can calculate the vector V as -

[tex]\overrightarrow V = |V|a_{u}[/tex] = 14 x [tex]\frac{1}{7} (3i + 6j + 2k)[/tex] = 2 (3i + 6j + 2k) = 6i + 12j + 4k

Hence, the vector [tex]\overrightarrow V[/tex] = 6i + 12j + 4k.

To solve more questions on vectors, visit the link below -

https://brainly.com/question/11866267

#SPJ2

A 15g block is sliding along horizontal plane and is given an initial velocity. The coefficient of kinetic friction between the plane and the block is 0.3. How far does the block travel before coming to a complete stop?

Answers

Answer:

3.67 meters

Explanation:

The question is incomplete without a value for the initial velocity, which i assume you meant to say it is 4.65 m/s

we will begin by applying the newtons second law of motion stated below

[tex]v^2 - u^2 = 2as[/tex]

Given data  

v = 0

u= 4.65 m/s

m= 15 g= 0.015 kg

μ= 0.3

we know that F= ma

  a = F/m

also F= -μR

and R= mg

i.e F= μmg

hence

a= -μmg/m = -μg  [minus sign because the acceleration is opposite the direction of motion]

 

Making s subject of formula we have

0 - u^2 = 2(-μg)s

s = U^2 / (2μg)

Substituting in the second equation of motion we have

[tex]=\frac{(4.65)^2}{ 2(0.3)(9.81) } \\\\\ = \frac {21.62}{ 5.88 } \\\\ =3.67 m[/tex]

 The block will go 3.67 meters before stopping

 

Rainwater draining from a neighborhood street initially travels at 4 ft/s through a pipe with a cross-sectional area of 15.7 ft2. This pipe connects down the street to another pipe with a cross-sectional area of 65.4 ft2. What would be the speed of the water as it moves through this larger pipe?

Answers

Answer:

The  velocity  is [tex]v_2 = 0.96 \ ft/s[/tex]

Explanation:

From the question we are told that

   The initial speed is  [tex]v_1 = 4 \ ft/s[/tex]

   The  cross -sectional area of the first pipe is  [tex]A_1 = 15.7 \ ft[/tex]

   The  cross -sectional area of the second pipe is [tex]A_2 = 65.4 \ ft[/tex]

Generally from continuity equation we have that

     [tex]A_1 * v_1 = A_2 * v_2[/tex]

So  

     [tex]v_2 = \frac{A_1 * v_1 }{A_2 }[/tex]

=>   [tex]v_2 = \frac{15.7 * 4 }{65.4 }[/tex]

=>   [tex]v_2 = 0.96 \ ft/s[/tex]

The only force acting on a 1.9 kg canister that is moving in an xy plane has a magnitude of 3.9 N. The canister initially has a velocity of 3.9 m/s in the positive x direction, and some time later has a velocity of 5.6 m/s in the positive y direction. How much work is done on the canister by the 3.9 N force during this time

Answers

Answer:

The work done on the canister is 15.34 J.

Explanation:

Given;

mass of canister, m = 1.9 kg

magnitude of force acting on x-y plane, F = 3.9 N

initial velocity of canister in positive x direction, [tex]v_i[/tex] = 3.9 m/s

final velocity of the canister in positive y direction, [tex]v_j = 5.6 \ m/s[/tex]

The change in the kinetic energy of the canister is equal to net work done on the canister by 3.9 N.

ΔK.E = [tex]W_{net}[/tex]

ΔK.E [tex]= K.E_f -K.E_i[/tex]

The initial kinetic energy of the canister;

[tex]K.E_i = \frac{1}{2} mv_i^2\\\\K.E_i = \frac{1}{2} m(\sqrt{v_i^2 +v_j^2 + v_z^2}\ )^2\\\\K.E_i = \frac{1}{2} *1.9(\sqrt{3.9^2 +0^2 + 0^2}\ )^2 = 14.45 \ J[/tex]

The final kinetic energy of the canister;

[tex]K.E_f =\frac{1}{2} mv_j^2 \\\\K.E_f = \frac{1}{2} m(\sqrt{v_i^2 +v_j^2 + v_z^2}\ )^2\\\\K.E_f = \frac{1}{2} *1.9(\sqrt{0^2 +5.6^2 + 0^2}\ )^2 = 29.79 \ J[/tex]

ΔK.E = 29.79 J - 14.45 J

ΔK.E = [tex]W_{net}[/tex] = 15.34 J

Therefore, the work done on the canister is 15.34 J.

Which event would most likely occur if Earth did not retain the heat from its formation? The inner core would liquefy. Seismic waves would move the crust. The Earth’s magnetic field would disappear. The asthenosphere and outer core would solidify.

Answers

Answer:

D-The asthenosphere and outer core would solidify.

Explanation:

The athenosphere is a region of the earth mantle below the lithosphere.

If the Sun didn’t retain the heat formed during its formation then it will have an adverse effect on other parts such as the core and mantle.The inner core wouldn’t liquefy but solidify. The asthenosphere and outer core would also solidify.

The Seismic waves wont be able to move the crust and the Earth’s magnetic field wouldn’t disappear but would be more pronounced.

The Earth’s magnetic field would disappear as well as solidification of asthenosphere and outer core will occur.

The asthenosphere and outer core would solidify and the Earth’s magnetic field would disappear if the Earth did not retain the heat from its formation because this heat make all the materials present in the outer core and asthenosphere in liquid form. This liquid form in the outer core is responsible for the generation of magnetic field around the earth.

If this heat will not retain in asthenosphere and outer core, the heat will escape and cooldown the asthenosphere and outer core which change it into solid form so the Earth’s magnetic field will be disappear so we can conclude that the Earth’s magnetic field would disappear as well as solidification of asthenosphere and outer core will occur if the Earth did not retain the heat from its formation.

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Suppose that a particular RC series circuit has a time constant of 5.0 seconds. What does that mean in terms of the charging and discharging

Answers

Answer:

Using the RC discharge and recharge table it means that after 5 time constant s there is a maximum current of 99.3% and a maximum voltage of 0.7% while form the charge table there will be a maximum voltage of 99.3% and maximum voltage of 0.7% in the RC CIRCUIT USIng

Vc/Vs= e^ -t/z for discharge and

Vc/Vs = e^(1-t/z) for charging

When asked how to create an electromagnet, the best answer would be:

"You can create an electromagnet by applying a direct current to a non–magnetic material in order to create an electromagnetic field."
"You can create an electromagnet by covering a wire with insulation and applying a direct electrical current to the magnet."
"You can create an electromagnet by coiling a ferromagnetic material, wrapping in an insulator, and applying a current to the coil."
"You can create an electromagnet by wrapping an insulated wire around a metal with ferromagnetic properties and applying an electric current."

Answers

Answer:

You can create an electromagnet by wrapping an insulated wire around a metal with ferromagnetic properties and applying an electric current."

Explanation:

Electromagnets are made by wrapping an insulated wire around a metal with ferromagnetic properties (example is iron), to form a loop, and then applying a current through the wire. Electromagnets can generate magnetism with a strong force field, and unlike normal magnets, their strength can be varied by varying the amount of current flowing through the coil. Their main disadvantage, which is also their most utilized property is that their magnetism is lost once the current flowing through the wire is cut-off.

Answer:

You can create an electromagnet by wrapping an insulated wire around a metal with ferromagnetic properties and applying an electric current."

Explanation:

I REALLY NEED HELP PLEASE!!! CAN SOMEONE ANSWER THIS? At 0 ºC, some amount of energy is required to change 1 kg of water from a solid into a liquid. If you had a 2 kg piece of ice, what effect would this have on the amount of thermal energy required to change the water from a solid to a liquid? A)It would require energy to be removed from the 2 kg piece of ice. The larger piece of ice already has more total energy than the smaller piece of ice, so energy must be removed for the ice to become liquid. B)It would require less energy to change solid water into liquid water because the energy would spread through the ice more quickly and the ice already has a larger total amount of energy because it is larger than a 1 kg piece of ice. C)It would require more energy to change solid water into liquid water because there are more molecules in this larger piece of ice. D)It would still require the same amount of energy to change solid water into liquid water because the entire piece of ice would still gain the same amount of energy in each case.

Answers

Answer:

C)It would require more energy to change solid water into liquid water because there are more molecules in this larger piece of ice.

Explanation:

c. it would require more energy to change ........

A 240-V rms 60-Hz supply serves a load that is 10 kW (resistive), 15 kVAR (capacitive), and 22 kVAR (inductive). Find:

Answers

This question is incomplete, the complete is;

A 240-V rms 60-Hz supply serves a load that is 10 kW (resistive), 15 kVAR (capacitive), and 22 kVAR (inductive). Find:

a) the apparent power

b) the current drawn from the supply

c) the kVAR rating and capacitance required to improve the power factor to 0.96 lagging

d) the current drawn from the supply under the power-factor conditions.

Answer:

a) value of apparent power 12.21 kVA

b) current drawn from the supply is 50.86∠-35° A

c) value of capacitance is 188.03 uF

d) value of current drawn from supply 43.4∠-16.26° A

Explanation:

a)

to calculate the value of apparent power, we say;

S = (10 × 10³) - (j15 × 10³) +( j22 × 10³ )

S = (10 - j15 + 22j ) × 10³

S = ( 10 + 17j ) KVA

now calculating the apparent power

║S║ = √ (( 10 × 10³) + (17j × 10³ ))

= √ ( 100 + 49 × 10³)

= 12.21 kVA

Therefore the value of apparent power 12.21 kVA

b)

we calculate the current drawn from the supply

S = VI°

I° = S/V

I° = (( 10 + 17j ) ₓ 10³) / 240

I° = ( 0.041467 + j0.029167)  × 10³

I°= 41.67 + j29.167 A

Therefore I = 41.67 - j29.167 A

I = 50.86∠-35° A

so current drawn from the supply is 50.86∠-35° A

c)

from S = { 10 + 17j  KVA, }

we calculate the power factor

∅₁ = tan⁻¹ ( Q / P )

∅₁ = tan⁺¹ ( 7 ₓ 10³ ) / ( 10 ₓ 10³)

∅₁ = tan⁻¹ ( 0.7 )

∅₁ = 35°

Now consider the new power factor, we know cos∅ form the question is 0.96

calculate the new value of power factor angle

∅₂ = cos⁻¹ ( 0.96 )

∅₂ = 16.26°

Now calculate the reduction in the reactive power caused by the shunt capacitor

Qc = Q₁ - Q₂

= P( tan∅₁ - tan∅₂ )

= ( 10 × 10³) (tan(35°) - tan(16.26°))

= ( 10 × 10³) ( 0.7 - 0.29166)

= (10⁴)(0.4083)

Qc = 4.083 kVAR

Now we Calculate value of capacitance

C = Qc / ωV²rms

C = (4.083 × 10³) / 2π(60) ( 240)²

C = (4.083 × 10³) / 21.715 × 10⁶

C = 1.8803 × 10⁻⁴

C = 188.03 uF

Therefore value of capacitance is 188.03 uF

d)

To calculate the current drawn from the new power factor condition, we say;

S₁ = P₁ + jQ₁

P₁ = P = 10 kW

Q₁ = Q - Qc = ( 7 - 4.083) × 10³ = 2.917 kVAR

S₁ = 10 + j2.917 kVAR

We calculate the value of current drawn from supply

S₁ = Vl₁°

l₁° = S₁ / V

l₁° = (10 + j2.917) × 10³ / 240

l₁° = ( 0.04167 + j0.012154) × 10³

l₁° = 41.67 + j12.15 A

So l₁ = 41.67 - j12.15 A

l₁ = 43.4∠-16.26° A

the value of current drawn from supply 43.4∠-16.26° A

A resistor has four colored stripes in the following order: orange, orange, brown and silver. What is the resistance of the resistor and its tolerance

Answers

Answer:

Resistance =330 Ω

Tolerance = 33 Ω

Explanation:

see attached resistor color code table

The first stripe is orange, which means the leftmost digit is a 3.

The second stripe is orange , which means the next digit is a 3.

The third stripe is brown.  Since brown is 1, it means add one zero to the right of the first two digits.

The resistance is:

orange-orange-brown=  330 Ω

The tolerance is:

The fourth color band indicates the resistor's tolerance.  Tolerance is the percentage of error in the resistor's resistance.

silver is 10%

A 330 Ω resistor has a silver tolerance band.  

Tolerance = value of resistor x value of tolerance band

= 330 Ω x 10% = 33 Ω

330 Ω stated resistance +/- 33 Ω tolerance means that the resistor could range in actual value from as much as 363 Ω to as little as 297 Ω.

The resistance of the resistor is 330 Ω and the tolerance is within  363 Ω and 297 Ω

In physics, resistor's resistance is coded using colors.

Orange colors are coded as 3

The  brown color is coded as 0

The silver color determines the tolerance and silver means 10%

The resistor with four colored stripes in the following order: orange, orange, brown has a resistance value of 330 Ω

Tolerance = 330 × 10%

Tolerance = 33Ω

Resistor value = 330±33

Resistor value = (330+33) and (330-33)

Resistor value = 363 Ω and 297 Ω

Hence the resistance of the resistor is 330 Ω and the tolerance is within  363 Ω and 297 Ω

Learn more here: https://brainly.com/question/18829138

A man in a boat is lookinh dtraight down at a fish in the water (n = 1.333) directly beneath him. The fish is looking straight up at the man. They are equidistant from the air/water interface. To the man, the fish appears to be 2.3 m beneath his eyes. To the fish, how far above its eyes does the man appear to be?

Answers

Answer:

To the fish the man appears to be 3.06m above its eyes

Explanation:

We know that refractive index n

n = real dept/ apparent depth

While apparent depth is the distance the fish appears to the man which is 2.3m so using the equation

Real dept= n x apparent depth

= 1.333* 2.3= 3.06m

Without his glasses, Isaac can see objects clearly only if they are less than 4.7 m from his eyes.

Required:
What focal length glasses worn 2.1 cmcm from his eyes will allow Isaac to see distant objects clearly?

Answers

Answer:

The focal length is  [tex]f = -4.721 \ m[/tex]

Explanation:

From the question we are told that

  The  image distance  is  [tex]v = 4.7 + (2.1 *10^{-2}) = - 4.721 \ m[/tex] the negative means  image is formed behind the lens

Generally the object distance is  [tex]u = \infty[/tex] this mean the light ray coming from the object are parallel to each other

So from lens equation

       [tex]\frac{1}{\infty } - \frac{1}{4.721} = \frac{1}{f}[/tex]

=>   [tex]f = -4.721 \ m[/tex]

The Vast Majority of all stars in the universe belong to which group?
A. White Dwarfs
B. Red Giants
C. Main Sequence
D. Supergiants​

Answers

Answer:

main sequence

Explanation:

because i think it is true

A 4.0 m length of gold wire is connected to a 1.5 V battery, and a current of 4.0 mA flows through it. What is the diameter of the wire? (The resistivity of gold is 2.44 × 10-8 Ω·m.) A. 9.0 μm B. 8.5 μm C. 17 μm D. 48 μm

Answers

Explanation:

Given that,

Length of gold wire, l = 4 m

Voltage of battery, V = 1.5 V

Current, I = 4 mA

The resistivity of gold, [tex]\rho=2.44\times 10^{-8}\ \Omega-m[/tex]

Resistance in terms of resistivity is given by :

[tex]R=\dfrac{\rho l}{A}[/tex]

Also, V = IR

So,

[tex]\dfrac{V}{I}=\dfrac{\rho l}{A}[/tex]

A is area of wire,

[tex]\dfrac{V}{I}=\dfrac{\rho l}{\pi r^2}[/tex], r is radius, r = d/2 (diameter=d)

[tex]\dfrac{V}{I}=\dfrac{\rho l}{\pi (d/2)^2}\\\\\dfrac{V}{I}=\dfrac{4\rho l}{\pi d^2}\\\\d=\sqrt{\dfrac{4\rho l I}{V\pi}} \\\\d=\sqrt{\dfrac{4\times 2.44\times 10^{-8}\times 4\times 4\times 10^{-3}}{1.5\times \pi}} \\\\d=18.2\ \mu m[/tex]

Out of four option, near option is (C) 17 μm.

The diameter of the wire is 18μm and the closest answer is option C.

The resistance of a wire is proportional to its length and inversely proportional to its area.

Given that a  4.0 m length of gold wire is connected to a 1.5 V battery, and a current of 4.0 mA flows through it. Then,

R = (ρL)/A

where

ρ = resistivity = 2.44 × 10-8 Ω·m

L = length

A = Area = [tex]\pi ^{2}[/tex]D/2

D = diameter of the wire

From Ohm's law, V = IR

make resistance R the subject of the formula

R = V/I

R = 1.5/4 x [tex]10^{-3}[/tex]

R = 375 Ω

Substitute all the parameters into the formula

R = (ρL)/A

375 = (2.44 × [tex]10^{-8}[/tex] x 4)/A

A = (9.76 × [tex]10^{-8}[/tex])/ 375

A = 2.603 x [tex]10^{-10}[/tex] [tex]m^{2}[/tex]

but

A =  [tex]\pi (D/2)^{2}[/tex]

2.603 x [tex]10^{-10}[/tex] =  [tex]\pi (D/2)^{2}[/tex]

[tex]\pi[/tex][tex]D^{2}[/tex] /4 = 2.603 x [tex]10^{-10}[/tex]

[tex]\pi[/tex][tex]D^{2}[/tex] = 1.04 x [tex]10^{-9}[/tex]

[tex]D^{2}[/tex] = (1.04 x [tex]10^{-9}[/tex])/ [tex]\pi[/tex]

D = [tex]\sqrt{3.3 * 10^{-10} }[/tex]

D = 1.8 x [tex]10^{-5}[/tex] m

D = 18 μm

Therefore, the diameter of the wire is 18μm and the closest answer is option C.

Learn more about Resistivity here: https://brainly.com/question/13735984

If a rigid body rotates about a fixed axis passing through its center of mass, the body's linear momentum is

Answers

Answer:

The linear momentum is zero

Explanation:

Because

When a rigid body is rotating about a fixed axis passing through point O, the body’s linear momentum given as L = mvG

But VG= 0 so

Linear momentum is zero

What is the correct tool to measure the volume of a cardboard box?

A) Balance
B)Metric ruler
C)graduated cylinder
D)thermometer
never mind i got it

Answers

Answer:

The correct answer is b

Explanation:

The volume of a solid box is the length (l) times the width (w)  times the height  (h)

         V = l w h

This distance must be measured with a tape measure, therefore the volume is also measured by the metric through the product of the three measurements.

The correct answer is b

A kayaker moves 26 meters southward, then 18 meters
northward, and finally 12 meters southward.
For this motion, what is the distance moved?
What is the magnitude and direction of the displacement?

Answers

Total distance: 56 meters. Magnitude and direction of displacement: 20 meters South.

Explanation:

The term distance refers to space between one point and other, or the total space a body or object covered while moving. In the case presented, this can be calculated by adding the partial distances given. This means the total distance is  56 meters as 26 meters + 18 meters + 12 meters = 56 meters.

On the other hand, displacement considers the distance from the initial position to the final position, and the direction of movement. This means partial distances should not be added but each movement should be considered according to the direction. The process is shown below:

-The first movement was 26 meters southward; this means by the end of this movement the distance between the initial position was 26 meters south.

- The second movement was 18 northward; this means the kayaker moved 18 meters towards the position. This changes the displacement to 8 meters South as 26 meters south - 18 meters north = 8 meters to the South.

-The last movement was 12 meters sound; this means the kayaker increased the distance from the original position 8 meters to the South + 12 meters to the South = 20 meters South (total displacement.)

If you shine an ultraviolet light on the metal ball of a negatively charged electroscope, what will happen

Answers

Answer:

The electroscope will become discharged by loosing electrons in a phenomenon called photoelectric effect

Explanation:

The UV light knocks off loosely bounded electrons in the outer shell causing the metal electroscope to discharge

Two narrow slits spaced 100 microns apart are exposed to light of 600 nm. At what angle does the first minimum (dark space) occur in the interference pattern

Answers

Answer:

The angle is   [tex]\theta = 0.1719^o[/tex]

Explanation:

From the question we are told that

   The  distance of separation is  [tex]d = 100 * 10^{-6} \ m[/tex]

    The  wavelength of light is  [tex]\lambda = 600 nm = 600 *10^{-9} \ m[/tex]

   

Generally the condition for destructive interference is mathematically represented as

         [tex]dsin(\theta ) =[m + \frac{1}{2} ]\lambda[/tex]

Here  m is the order of maxima,  first minimum (dark space) m = 0

 So  

      [tex]100 *10^{-6 } * sin(\theta ) =[0 + \frac{1}{2} ]600 *10^{-9}[/tex]

=>   [tex]\theta = sin^{-1} [0.003][/tex]

=>   [tex]\theta = 0.1719^o[/tex]

     

Let k be the Boltzmann constant. If the configuration of the molecules in a gas changes so that the multiplicity is reduced to one-third its previous value, the entropy of the gas changes by:__________. A) S = 3kln2 B) S =

Answers

Answer:

ΔS =  - k ln (3)

Explanation:

Using the Boltzmann's expression of entropy, we have;

S = k ln Ω

Where;

S = Entropy

Ω = Multiplicity

From the question, the configuration of the molecules in a gas changes so that the multiplicity is reduced to one-third its previous value. This also causes a change in the entropy of the gas as follows;

ΔS = k ln (ΔΩ)

ΔS = kln(Ω₂)  - kln(Ω₁)

ΔS = kln(Ω₂ / Ω₁)              -------------(i)

Where;

Ω₂ = Final/Current value of the multiplicity

Ω₁ = Initial/Previous value of the multiplicity

Ω₂ = [tex]\frac{1}{3}[/tex] Ω₁         [since the multiplicity is reduced to one-third of the previous value]

Substitute these values into equation (i) as follows;

ΔS = k ln ([tex]\frac{1}{3}[/tex] Ω₁ / Ω₁)

ΔS = k ln ([tex]\frac{1}{3}[/tex])

ΔS = k ln (3⁻¹)

ΔS =  - k ln (3)

Therefore, the entropy changes by - k ln (3)

Write the name of the law for each of the equations and explain in one or two lines how the two sides are related maxwells equation.

Answers

Answer:

Lorenz force law

Explanation:

The equation given name after the physicist and the mathematician James Clerk  Maxwell. He published his first equation in 1861 and 1862 that included the Lorenz force law. These equation were used by Maxwell first of all for the light in electromagnetic phenomena.

In his equations Maxwell proposed that how the electric and magnetic field is fluctuate and constant speed in the vacuum which is called a electromagnetic radiation.

These are waves that occurs at different level of wavelength spectrum. These equation have two major variant such as universal applicability. The Maxwell equations are used for the Equivalent alternative formulation.

Consider a conducting rod of length 34 cm moving along a pair of rails, and a magnetic field pointing perpendicular to the plane of the rails.

Required:
At what speed (in m/s) must the sliding rod move to produce an emf of 0.75V in a 1.75T field?

Answers

Answer:

The speed is  [tex]v= 1.26 \ m/s[/tex]

Explanation:

From the question we are told that

   The  length of the rod is  [tex]l = 34 \ cm = 0.34 \ m[/tex]

    The  induced emf is [tex]\epsilon = 0.75\ V[/tex]

    The  magnetic field is [tex]B = 1.75 \ T[/tex]

Generally the speed is mathematically represented as

       [tex]v = \frac{\epsilon }{Bl }[/tex]

=>    [tex]v = \frac{ 0.75 }{1.75 * 0.34 }[/tex]

=>   [tex]v= 1.26 \ m/s[/tex]

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