The complete question is;
A positive point charge Q is fixed on a very large horizontal frictionless tabletop. A second positive point charge q is released from rest near the stationary charge and is free to move. Which statement best describes the motion of q after it is released?
A) Its speed will be greatest just after it is released.
B) Its acceleration is zero just after it is released.
C) As it moves farther and farther from Q, its speed will keep increasing
D) As it moves farther and farther from Q, its acceleration will keep increasing.
Answer:
Option C - As it moves farther and farther from Q, its speed will keep increasing.
Explanation:
We are told that when a second positive point charge(q) is released from rest near the stationary charge and it's free to move. Thus, the stationary charge will now exert a repulsive force upon thus second positive point charge and it will go on decreasing because the mobile charge will move away from the stationary charge. Thus, it will have a decreasing but positive acceleration . So we can conclude that it's velocity will keep increasing but it will be at a declining rate.
Thus, the correct answer is;
Option C - As it moves farther and farther from Q, its speed will keep increasing.
The Vast Majority of all stars in the universe belong to which group?
A. White Dwarfs
B. Red Giants
C. Main Sequence
D. Supergiants
Answer:
main sequence
Explanation:
because i think it is true
A 76-W incandescent light bulb operates at 120 V. How many electrons and coulombs flow through the bulb in one day?
Answer:
43200c
Explanation:
A square coil with a side length of 16.0 cm and 29 turns is positioned in a region with a horizontally directed, spatially uniform magnetic field of 83.0 mT and set to rotate about a vertical axis with an angular speed of 1.20 ✕ 102 rev/min.
(a) What is the maximum emf induced in the spinning coil by this field?
___V
(b) What is the angle between the plane of the coil and the direction of the field when the maximum induced emf occurs? (Enter the angle with the smallest possible magnitude.)
___°
Answer:
A
[tex]\epsilon_{max} = 0.774 \ V[/tex]
B
[tex]wt = 0^o[/tex]
Explanation:
From the question we are told that
The length of the side is [tex]l = 16.0 \ cm = 0.16 \ m[/tex]
The number of turns is [tex]N = 29 \ turns[/tex]
The magnetic field is [tex]B = 83.0 mT = 83 *10^{-3} \ T[/tex]
The angular speed is [tex]w = 1.20 * 10^2 rev/min = \frac{1.20 *10^2 * 2\pi}{60 } = 12.6 \ rad/s[/tex]
Generally the area is [tex]A = l^2[/tex]
Generally the induced emf is mathematically represented as
[tex]\epsilon = N * w * B * A * cos(wt)[/tex]
At maximum [tex]cos(wt) = 1[/tex]
So
[tex]\epsilon_{max} = N * w * B * A[/tex]
[tex]\epsilon_{max} = 29 * 12.6 * 83*10^{-3}* (l^2)[/tex]
=> [tex]\epsilon_{max} = 29 * 12.6 * 83*10^{-3}* ((0.16)^2)[/tex]
=> [tex]\epsilon_{max} = 0.774 \ V[/tex]
At maximum emf
[tex]cos (wt) = 1[/tex]
=> [tex](wt) = cos^{-1} (1)[/tex]
=> [tex]wt = 0^o[/tex]
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
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
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.
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
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.
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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A 240-V rms 60-Hz supply serves a load that is 10 kW (resistive), 15 kVAR (capacitive), and 22 kVAR (inductive). Find:
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 nearsighted woman has a far point of 180 cm . Part A. What kind of lens, converging or diverging, should be prescribed for her to see distant objects more clearly?Part B. What power should the lens have?
Explanation:
It is given that,
A nearsighted woman has a far point of 180 cm.
The object distance for nearsightedness is infinity, u = ∞
The image distance is, v = -180 cm
Using lens formula,
[tex]\dfrac{1}{f}=\dfrac{1}{v}-\dfrac{1}{u}\\\\\dfrac{1}{f}=\dfrac{1}{(-180)}-\dfrac{1}{\infty}\\\\f=-180\ cm\\\\f=-1.8\ m[/tex]
For nearsightedness, a diverging lens is used.
Power of the lens,
P = 1/f
[tex]P=\dfrac{1}{-1.8}\\\\P=-0.56\ D[/tex]
So, the power of the lens is -0.56 D.
The power of lens to be prescribed is 3.5 D.
A person that is far sighted can see far objects clearly but not nearby objects. The farpoint of a normal eye is infinity. Far sightedness is corrected by the use of a convex lens. The near point of the normal eye is 25 cm.
We have that;
u = 25 cm
v = -180 cm
1/f = 1/u - 1/v
1/f = 1/25 - 1/180
1/f = 0.04 - 0.0056
f = 29 cm
Power of lens = 100/f = 100/29 = 3.5 D
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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?
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.)
Convert 50km/hr into m/s using dimensional analysis?
Answer:
Explanation:
1 km=1000 m
1 hour =60 min =60*60 sec=3600 sec
Now put 1000 m instead of km and 3600 sec instead of hour in the given expression.
=50 km/hour
=50*1000 m/3600 sec
=500 m/36 sec
=13.89 m/s
Answer:
= 13.89 m/s
Explanation:
km 1000 m 1 hr
50 ----- x ---------- x ------------
hr 1 km 3600 secs
= 13.89 m/s
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 =
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)
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
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 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
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.
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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.
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.
If you shine an ultraviolet light on the metal ball of a negatively charged electroscope, what will happen
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
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
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
The magnetic field of a plane-polarized electromagnetic wave moving in the z-direction is given by in SI units. What is the frequency of the wave
Answer:
[tex]f=1.98\times 10^5\ Hz[/tex]
Explanation:
The magnetic field of a plane-polarized electromagnetic wave moving in the z-direction is given by :
[tex]B=1.2\times 10^{-6}\sin [2\pi (\dfrac{z}{240}-\dfrac{10^7t}{8})][/tex] .....(1)
The general equation of the magnetic field wave is given by :
[tex]B=B_o\sin (kz-\omega t)[/tex] ....(2)
Equation (1) is in form of equation (2), if we compare equation (1) and (2) we find that,
[tex]\omega=\dfrac{10^7}{8}[/tex]
We need to find the frequency of the wave. It is given by :
[tex]f=\dfrac{\omega}{2\pi}\\\\f=\dfrac{10^7}{8\times 2\pi}\\\\f=1.98\times 10^5\ Hz[/tex]
So, the frequency of the wave is [tex]1.98\times 10^5\ Hz[/tex]
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.
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
The electric field in a traveling em wave in the vacuum has an rms intensity of 6.75 v/m.
Required:
Calculate the amount of energy delivered in average during 3.02x10^7s to 2.00 cm^2 of a wall that it hits perpendicularly?
Answer:
The amount of energy delivered is 730.84 J
Explanation:
Given;
rms intensity of the electric field, [tex]E_{rms}[/tex] = 6.75 v/m
area of the wall, A = 2.0 cm² = 2.0 x 10⁻⁴ m²
The average intensity of the wave is given by;
[tex]I_{avg} = c \epsilon_o E_{rms}^2[/tex]
where;
c is the speed of light
ε₀ is permittivity of free space
I = (3 x 10⁸)(8.85 x 10⁻¹²)(6.75)²
I = 0.121 W/m²
Average power delivered, P = I x A
P = 0.121 x 2 x 10⁻⁴
P = 2.42 x 10⁻⁵ W
The amount of energy delivered is calculated as;
E = P x t
E = 2.42 x 10⁻⁵ x 3.02 x 10⁷
E = 730.84 J
Therefore, the amount of energy delivered is 730.84 J
A coiled telephone cord forms a spiral with 52.0 turns, a diameter of 1.30 cm, and an unstretched length of 57.5 cm. Determine the inductance of one conductor in the unstretched cord.
Answer:
The inductance of one conductor in the unstretched cord is 0.7849 μH
Explanation:
Given;
number of turns of the coil, N = 52 turns
diameter of the coil, d = 1.30 cm
radius of the coil, r = d/2 = 1.30 cm / 2 = 0.65 cm = 0.0065 m
length of the unstretched cord, l = 57.5 cm = 0.575 m
The inductance of one conductor in the unstretched cord is given by;
[tex]L = \frac{N^2 \mu_o A}{l}[/tex]
where;
μ₀ is permeability of free space = 4π x 10⁻⁷ m/A
A is area of coil, = πr² = π x (0.0065)² = 1.328 x 10⁻⁴ m²
[tex]L = \frac{(52)^2(4\pi *10^{-7})(1.328*10^{-4})}{0.575} \\\\L = 7.849*10^{-7} \ H[/tex]
L = 0.7849 μH
Therefore, the inductance of one conductor in the unstretched cord is 0.7849 μH
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."
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:
A beam of light in air strikes a slab of glass (n = 1.52) and is partially reflected and partially refracted and partially refracted, find the angle of incidence if the angle of reflection is twice the angle of refraction.
θ1= (answer in degress)
Answer:
Explanation:
angle of reflection = angle of incidence i = 2θ
angle of refraction r = θ
sin i / sin r = 1.52
sin2θ / sin θ = 1.52
2 sinθ . cosθ / sin θ = 1.52
2 cosθ = 1.52
cosθ = .76
θ= 41°
Hence angle of incidence = 41°
.
A truck covered 2/7 of a journey at an average speed of 40
mph. Then, it covered the remaining 200 miles at another
average speed. If the average for the whole journey was 35
mph, what was the amount of time for the whole journey?
h
Answer:
The amount of time for the whole journey is 8 hours.
Explanation:
A truck covered 2/7 of a journey at an average speed of 40 mph. Representing 1 the total of the trip traveled, then the rest of the distance traveled is calculated as: [tex]1-\frac{2}{7} =\frac{5}{7}[/tex]
So if the truck covered the remaining 200 miles at [tex]\frac{2}{7}[/tex], this means that [tex]\frac{5}{7}[/tex] of the trip represents the 200 miles. So, to calculate the total distance traveled by the truck, you apply the following rule of three: if [tex]\frac{5}{7}[/tex] of the route represents 200 miles, the integer 1 (which represents the total of the route), how many miles are they?
[tex]miles=\frac{1*200miles}{\frac{5}{7} } =\frac{7}{5} *200 miles[/tex]
miles= 280
So the total distance traveled is 280 miles. Since speed is the relationship between the space traveled by an object and the time used for it ([tex]speed=\frac{distance}{time}[/tex]), then if the average of the entire trip was 35 mph and the distance traveled 280 miles, the time is calculated as:
[tex]time=\frac{distance}{speed}=\frac{280 miles}{35 mph}[/tex]
time= 8 h
The amount of time for the whole journey is 8 hours.
If a rigid body rotates about a fixed axis passing through its center of mass, the body's linear momentum is
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
Which statement describes a force acting on an object?
A.a person sees a rolling ball toward him
B. A magnet pulls a nail toward it
C. A piece of charcoal burns in a grill.
D.A car is parked on the street
Answer: B. A magnet pulls a nail towards it
Explanation: Out of the list of answers, this is the only answer where a force is acting on an object. the act of the magnet pulling on the nail is the force, and the nail is the object.
An unmanned spacecraft is in a circular orbit around the moon, observing the lunar surface from an altitude of 43.0 km . To the dismay of scientists on earth, an electrical fault causes an on-board thruster to fire, decreasing the speed of the spacecraft by 23.0 m/s .If nothing is done to correct its orbit, with what speed (in km/h) will the spacecraft crash into the lunar surface?
Answer: v₂ = 5962 km
the spacecraft will crash into the lunar surface at a speed of 5962 km if nothing is done to correct its orbits
Explanation:
Given that;
Lunar surface is in an altitude h = 43.0 km = 43 × 10³ m
we know; Radius of moon R₁ = 1.74 × 10⁶, mass of moon = 7.35 × 10²²
speed of the space craft when it crashes into the lunar surface , v
decreasing speed of the space craft = 23 m/s
Now since the space craft travels in a circular orbit, we use centrifugal expression Fe = mv²/r
but the forces is due to gravitational forces between space craft and lunar surface Fg = GMn/r²
HERE r = Rm + h
we substitute
r = 1.74 × 10⁶ m + 43 × 10³ m
= 1.783 × 10⁶ m
On equating these, we have
G is gravitational force ( 6.673 × 10⁻¹¹ Nm²/kg²)
v²/r = GM/r²
v = √ ( GM/r)
v = √ ( 6.673 × 10⁻¹¹ Nm²/kg² × 7.35 × 10²² / 1.783 × 10⁶ )
v = √ (2750787.9978)
v = 1658.55 m/s
Now since speed is decreasing by 23 m/s
the speed of the space craft into the lunar face is,
v₁ = 1658.55 m/s - 23 m/s
v₁ = 1635.55 m/s
Now applying conversation of energy, we say
1/2mv₂² = 1/2mv₁² + GMem (1/Rm - 1/r)
v₂ = √ [ v₁² + GMe (1/Rm - 1/r)]
v₂ = √ [ 1635.55² + ( 6.673 × 10⁻¹¹ Nm²/kg² × 7.35 × 10²²) (1/ 1.74 × 10⁶ - 1 / 1.783 × 10⁶)]
v₂ = √ (2675023.8025 + 67979.24)
v₂ = √(2743003.046)
v₂ = 1656.2 m/s
now convert
v₂ = 1656.2 × 1km/1000m × 3600s/1hrs
v₂ = 5962 km
Therefore the spacecraft will crash into the lunar surface at a speed of 5962 km if nothing is done to correct its orbits
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
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
Can you come up with a mathematical relationship, based on your data that shows the relationship between distance from the charges and electric field strength?
Answer:
The relationship is [tex]E=\frac{ kQ}{d^2}[/tex]
Explanation:
The electric field strength is denoted by the symbol E,
the test charge is denoted be q and the source charge be Q
distance is denoted by d
Then the equation can be rewritten in symbolic form as
Electric field strength is = Force/charge
[tex]E=\frac{F}{q}------1[/tex]
we know that the formula for force is given as
[tex]F= \frac{kQq}{d^2} ------2[/tex]
where [tex]k= 9*10^9 N.m^2/C^2[/tex]
and d is the separation distance between charges
We can insert the expression for Force in equation one
we have
[tex]E= \frac{kQ\sout{q}/d^2}{\xout{q}}--------3[/tex]
We can strike out both qs in the numerator and denominator we have
[tex]E=\frac{ kQ}{d^2}[/tex]
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?
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
A 12.0-g sample of carbon from living matter decays at the rate of 162.5 decays/minute due to the radioactive 14C in it. What will be the decay rate of this sample in 1000 years? What will be the decay rate of this sample in 50000 years?
Answer:
a)143.8 decays/minute
b)0.41 decays/minute
Explanation:
From;
0.693/t1/2 = 2.303/t log (Ao/A)
Where;
t1/2=half-life of C-14= 5670 years
t= time taken to decay
Ao= activity of a living sample
A= activity of the sample under study
a)
0.693/5670 = 2.303/1000 log(162.5/A)
1.22×10^-4 = 2.303×10^-3 log(162.5/A)
1.22×10^-4/2.303×10^-3 = log(162.5/A)
0.53 × 10^-1 = log(162.5/A)
5.3 × 10^-2 = log(162.5/A)
162.5/A = Antilog (5.3 × 10^-2 )
A= 162.5/1.13
A= 143.8 decays/minute
b)
0.693/5670 = 2.303/50000 log(162.5/A)
1.22×10^-4 = 4.61×10^-5 log(162.5/A)
1.22×10^-4/4.61×10^-5 = log(162.5/A)
0.26 × 10^1 = log(162.5/A)
2.6= log(162.5/A)
162.5/A = Antilog (2.6 )
A= 162.5/398.1
A= 0.41 decays/minute