Answer:
A=1526N/m
B =40cm
Explanation:
Step one;
given
initial length=27cm= 0.27m
final length= 31.5cm= 0.315m
mass m= 7kg
Step two:
Required
A.
Force= mg
Force=weight= 7*9.81= 68.67N
extenstion e
e=31.5-27=4.5cm= 0.045m
K= spring constant
we know that F=ke
k=F/e
k=68.67/0.045
k=1526N/m
B.
New weight= 205N
F=ke
e=205/1526
e=0.13m
new length = 0.13+0.27= 0.4m
to cm=0.40*100=40cm
A primary coil of a transformer is connected to a 120V/60Hz wall outlet. The secondary coil is connected to a lamp that dissipates 60 W. How do I find the rms current in the primary coil?
Answer:
0.5Amperes
Explanation:
Using the conservation of power formula
P = VI
The power we have in this coil is given as
P = 60 watts
Then we have V = 120 watts
Such that when we put these values into the formula above we will get:
60 = 120I
Then when we divide through by 120:
I = 60/120
I = 0.5 amperes
So 0.5 amperes is the rms in the primary coil.
Zinc is electroplated from a ZnSO4 solution. How many grams of zinc will be deposited if a 1.6A current runs for 25 minutes?
Answer:
0.817g
Explanation:
Zn2+ + 2e -----> An
Amount of electricity used
Q = It
= 1.6A x 25 x 60 seconds
= 2400 coulomb's
Number of moles of electrons = Q/f
F = 96500 coulomb's
= 2400/96500
= 0.025mol
From the equation above,
We see that the number of Zn moles firmed is equal to half the number of electrons used.
Molecular weight of Zn = 65.38
0.025x65.38/2
= 0.817 grams of zinc
Thank you!
A heavy object and a light object are dropped from the same height. If we neglect air resistance, which will hit the ground first?
Answer:
None, both objects will hit ground at the same time.
Explanation:
Assuming no air resistance present, and that both objects start from rest, we can apply the following kinematic equation for the vertical displacement:[tex]\Delta h = \frac{1}{2}*g*t^{2} (1)[/tex]
As the left side in (1) is the same for both objects, the right side will be the same also.Since g is constant close to the surface of the Earth, it's also the same for both objects.So, the time t must be the same for both objects also.The work function for a metal surface is 3.82 eV. What is the largest wavelength of light in nm that will produce photoelectrons from this surface?1 eV = 1.602 ? 10?19 J,
e = 1.602 ? 10?19 C,
c = 2.998 ? 108 m/s,
and
h = 6.626 ? 10?34 J
Answer:
The largest wavelength of light that will produce photoelectrons from this surface is 324.6 nm.
Explanation:
Given;
work function, Ф = 3.82 eV
The work function of the metal is minimum energy required to produce electron from the metal surface.
Ф = hf
where;
h is Planck's constant = 6.626 x 10⁻³⁴ J/s
f is the frequency of the photon
f = c / λ
[tex]\phi = \frac{hc}{\lambda}[/tex]
where;
c is speed of light = 2.998 x 10⁸ m/s
λ is the wavelength = ?
[tex]\phi = \frac{hc}{\lambda}\\\\\lambda = \frac{hc}{\phi }\\\\\lambda = \frac{(6.626*10^{-34})(2.998*10^8)}{3.82*1.602*10^{-19}}\\\\\lambda = 3.246*10^{-7} \ m\\\\\lambda = 324.6 *10^{-9} \ m\\\\\lambda = 324.6 \ nm[/tex]
Therefore, the largest wavelength of light that will produce photoelectrons from this surface is 324.6 nm.
This object was observed in 1997.
The object in the picture is ____ a/an .
Answer: Hale-Bopp was an unusually bright comet that flew by Earth, reaching its closest approach to the planet in 1997.
Explanation:
Hale-Bopp is the answer
Answer: This is Comet Hale--Bopp
Explanation:
6kg of cold water at 10°c is added to 6kg of hot water of 100°c what is the value of temp after the water is mixed
Explanation:
so sorry
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don't know but please mark me as brainliest please
Q.16 :-If the amplitude of a vibrating membrane is increased by 50%, then the loudness of sound will
increase by
50%
100%
125%
150%
Answer:
B. 100%
Explanation:
When the amplitude of a vibrating membrane increases the loudness of sound increases. Higher amplitude waves will mean more energy and greater intensity which causes the sound to be louder.
Loudness is proportional to the square of the amplitude. This will simply mean when the amplitude of a wave is doubled, the sound will be 4 times louder.
In this case, 50% increase in the amplitude of a vibrating membrane will cause a 100% increase in the loudness of sound.
A 4.0-kg object is supported by an aluminum wire of length 2.0 m and diameter 2.0 mm. How much will the wire stretch?
Answer:
The extension of the wire is 0.362 mm.
Explanation:
Given;
mass of the object, m = 4.0 kg
length of the aluminum wire, L = 2.0 m
diameter of the wire, d = 2.0 mm
radius of the wire, r = d/2 = 1.0 mm = 0.001 m
The area of the wire is given by;
A = πr²
A = π(0.001)² = 3.142 x 10⁻⁶ m²
The downward force of the object on the wire is given by;
F = mg
F = 4 x 9.8 = 39.2 N
The Young's modulus of aluminum is given by;
[tex]Y = \frac{stress}{strain}\\\\Y = \frac{F/A}{e/L}\\\\Y = \frac{FL}{Ae} \\\\e = \frac{FL}{AY}[/tex]
Where;
Young's modulus of elasticity of aluminum = 69 x 10⁹ N/m²
[tex]e = \frac{FL}{AY} \\\\e = \frac{(39.2)(2)}{(3.142*10^{-6})(69*10^9)} \\\\e = 0.000362 \ m\\\\e = 0.362 \ mm[/tex]
Therefore, the extension of the wire is 0.362 mm.
How much work is it to lift a 20. kg sack of potatoes vertically 6.5 m?
Calculate the gravitational potential energy of a 8.6-kg mass on the surface of the Earth. Express your answer using two significant figures.
Answer:
The gravitational potential energy of the 8.6 kg mass is 5.38x10⁸ J.
Explanation:
We can find the gravitational potential energy of the mass using the following equation:
[tex] E_{p} = m*g*h [/tex]
Where:
m: is the mass = 8.6 kg
g: is the gravity = 9.81 m/s^{2}
h: is the height = Earth's radius = 6371 km
Hence, we have:
[tex]E_{p} = 8.6 kg*9.81 m/s*6371000 m = 5.38 \cdot 10^{8} J[/tex]
Therefore, the gravitational potential energy of the 8.6 kg mass is 5.38x10⁸ J.
I hope it helps you!
If a dog runs 25m east and then turns around and runs
back 20 west, what is the total distance ran? How far is the
dog displacement from the starting line?
Answer:
The dog ran a total distance of 45m but he is only 5m away from the starting line
Explanation: When you add 25 to 20 you get 45 for the total distance and if he ran back in the same direction then you would subtract 20 from 25 and get 5m
How do inkblots show your personality?
---
A. Inkblots rely on creativity.
B.Your description of an inkblot will give deeper meaning of your inner ideas.
C. Inkblot responses are a way to test if you're lying.
D. Inkblot tests were never reliable to use.
Answer:
B
Explanation:
Examples of ink blots would be Faceless women, Rocket or Tower, Roast chicken which gives more meaning of your personality and you yourself of the picture that is shown.
Many behavioral psychologists would disagree with the social cognitive theory because most believe that behavior is __________. A. affected by cognition B. not affected by cognition C. affected by conditioning D. not affected by conditioning (psychology)
Its B: not affected by cognition
The correct answer B. Not affected by cognition
Explanation:
In the Social Cognitive Theory, the most important aspects are social interaction and cognition that involves mental processes such as comprehension. Indeed, this theory proposes behaviors are the result of observing other people as part of social interaction, understanding this behavior, and then imitating it.
Despite this, many psychologists do not support this theory and the main reason is that they deny the learning of behavior is related to cognition or complex mental processes. Instead, some believe behavior is the result of certain impulses or that is regulated by conditioning such as behaving correctly to avoid negative consequences.
Answer:
B. is correct on Edge 2020
Explanation:
Peace and Love
Which of these statements about mixtures is true? (2 points)
a
Mixtures are made up of elements bonded together.
b
Elements and compounds are types of mixtures.
c
Pure substances are made up of mixtures combined in specific ratios.
d
Mixtures are classified based on the distribution of particles in them.
Answer:A
Explanation:
Answer:
D. Mixtures are classified based on the distribution of particles in them.
Explanation:
A is wrong because mixtures are not made of elements that are bonded together chemically.
B is wrong because elements and compounds are types of pure substances.
C is wrong because pure substances are not made up of mixtures.
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In a police ballistics test, 2.00-g bullet traveling at 700 m/s suddenly hits and becomes embedded in a stationary 5.00-kg wood block. Does the bullet gain or lose momentum?
Answer:
The bullet will lose momentum
Explanation:
mass of the bullet, m₁ = 2.0 g = 0.002 kg
initial velocity of the bullet, u₁ = 700 m/s
mass of the wood block, m₂ = 5 kg
initial velocity of the wood block, u₂ = 0
let the final velocity of the bullet-block system after collision = v
Apply the principle of conservation of linear momentum;
m₁u₁ + m₂u₂ = v(m₁ + m₂)
(0.002 x 700) + (5 x 0) = v(0.002 + 5)
1.4 = 5.002 v
v = 1.4 / 5.002
v = 0.28 m/s
Change in momentum of the bullet is given by;
ΔP = m₁v - m₁u₁
ΔP = m₁(v - u₁)
ΔP = 0.002( 0.28 - 700)
ΔP = -1.4 kg.m/s
Therefore, the bullet will lose momentum
The engine of a model airplane must both spin a propeller and push air backward to propel the airplane forward. Model the propeller as three 0.30-m-long thin rods of mass 0.040 kg each, with the rotation axis at one end.
What is the moment of inertia of the propeller?
How much energy is required to rotate the propeller at 5800 rpm? Ignore the energy required to push the air.
Solution :
Given :
Length of the propeller rods, L =0.30 m
Mass of each, M = 0.040 kg
Moment of inertia of one propeller rod is given by
[tex]$I=\frac{1}{3}\times M \times L^2$[/tex]
Therefore, total moment of inertia is
[tex]$I=3 \times \frac{1}{3}\times M \times L^2$[/tex]
[tex]$I=M\times L^2$[/tex]
[tex]$I=0.04\times (0.3)^2$[/tex]
[tex]$0.0036 \ kg \ m^2$[/tex]
Now energy required is given by
[tex]$E=\frac{1}{2}\times I \times \omega^2 $[/tex]
where, angular speed, ω = 5800 rpm
[tex]$\omega = 5800 \times \frac{2 \pi}{60} $[/tex]
= 607.4 rad/s
Therefore energy,
[tex]$E=\frac{1}{2}\times 0.0036 \times (607.4)^2 $[/tex]
= 664.1 J
The moment of inertia of the propeller is 0.0036 kgm² and the energy required is 663.21 J
Energy required for propeller:Given that the mass of the propellers is m = 0.040kg,
and their length is L = 0.30m
The moment of inertia of a rod with the rotation axis at one end is given by :
[tex]I = \frac{1}{3}m L^2[/tex]
so for 3 propellers:
[tex]I=3\times\frac{1}{3}\times(0.04)\times(0.3)^2[/tex]
I = 0.04 × 0.09
I = 0.0036 kgm²
Now, the frequency is given f = 5800 rpm
so anguar speed, ω = 5800×(2π/60)
ω = 607 rad/s
Energy required:
E = ¹/₂Iω²
E = 0.5 × 0.0036 × (607)² J
E = 663.21 J
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n LC circuit has an oscillation frequency of 105 Hz. If C = 0.1 F , then L must be about:
Answer:
L = 22.97 H
Explanation:
Given that,
Capacitance, [tex]C=0.1\ \mu F=0.1\times 10^{-6}\ F[/tex]
Oscillation frequency, f = 0.5 Hz
The frequency of an AC circuit is given by :
[tex]f=\dfrac{1}{2\pi \sqrt{LC} }[/tex]
Where
L is impedance
[tex]f^2=\dfrac{1}{4\pi ^2LC}\\\\L=\dfrac{1}{4\pi ^2 f^2 C}\\\\\text{Putting all the values}\\\\L=\dfrac{1}{4\pi^2 \times (105)^2\times 0.1\times 10^{-6}}\\\\L=22.97\ H[/tex]
So, the impedance of LC circuit 22.97 H.
A conductor of uniform radius 1.20 cm carries a current of 3.00 A produced by an electric field of 120 V/m. What is the resistivity of the material?
Answer:
The value is [tex]\rho = 0.0180 97 9 \ \Omega m^{-1}[/tex]
Explanation:
From the question we are told that
The radius of the conductor is [tex]r = 1.20 \ cm = 0.012 \ m[/tex]
The current it is carrying is [tex]I = 3.00 \ A[/tex]
The electric field is [tex]E = 120 \ V/m[/tex]
Generally the resistivity of the material is mathematically represented as
[tex]\rho = \frac{EA}{ I }[/tex]
Here A is the area of the conductor which is mathematically represented as
[tex]A = \pi r^2[/tex]
=> [tex]A =3.142 * (0.012)^2[/tex]
=> [tex]A = 0.000452 \ m^2[/tex]
So
[tex]\rho = \frac{120 * 0.000452}{ 3 }[/tex]
=> [tex]\rho = 0.0180 97 9 \ \Omega m^{-1}[/tex]
Given values,
Radius, r = 1.20 m or 0.012 mCurrent, I = 3.00 AElectric field, E = 120 V/mNow,
The area of conductor,
→ [tex]A = \pi r^2[/tex]
[tex]= 3.142\times (0.012)^2[/tex]
[tex]= 0.000452 \ m^2[/tex]
hence,
The resistivity will be:
→ [tex]\rho = \frac{EA}{I}[/tex]
By substituting the values, we get
[tex]= \frac{120\times 0.000452}{3}[/tex]
[tex]= 0.0180979 \ \Omega m^{-1}[/tex]
Thus the above response is right.
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which force is a nonconact force?
a. raft floating on water
b. all normal forceses
c. a person pulling a wagon
d, magnetic attracting metal
Answer:
d, magnetic attracting metal, because the force is still going on without the magnet touching metal, and you cant see the force
Explanation:
Hope this helps <33
A graph showing the kinetic energy and speed of a moving object is provided.
KE (Joules)
Speed (m/s)
Which of the following can be concluded from the graph?
Kinetic energy only changes when speed changes.
Speed is only related to the size of an object.
Kinetic energy increases as speed increases.
All moving objects have the same kinetic energy.
its the 3rd one kinetic energy increases as speed increases
A parallel-plate capacitor has plates of area 0.40 m2 and plate separation of 0.20 mm. The capacitor is connected to a 9.0 V battery. (a) What is the electric field between the plates?(b) What is the capacitance of the capacitor?
(c) What is the magnitude of the charge on each plate of the capacitor?
Answer:
a) E = 4.5*10⁴ V/m
b) C= 17.7 nF
c) Q = 159. 3 nC
Explanation:
a)
By definition, the electric field is the electrostatic force per unit charge, and since the potential difference between plates is just the work done by the field, divided by the charge, assuming a uniform electric field, if V is the potential difference between plates, and d is the separation between plates, the electric field can be expressed as follows:[tex]E = \frac{V}{d} = \frac{9.0V}{2*10-4m} =4.5 * 10e4 V/m (1)[/tex]
b)
For a parallel-plate capacitor, applying the definition of capacitance as the quotient between the charge on one of the plates and the potential difference between them, and assuming a uniform surface charge density σ, we get:[tex]Q = \sigma* A (2)[/tex]
From (1), we know that V = E*d, but at the same time, applying Gauss'
Law at a closed surface half within the plate, half outside it , it can be
showed than E= σ/ε₀, so finally we get:
[tex]C = \frac{Q}{V} =\frac{\sigma*A}{E*d} = \frac{\sigma*A}{\frac{\sigma}{\epsilon_{o} } d} =\frac{\epsilon_{0}*A}{d} = \frac{8.85e-12F/m*0.4m2}{2e-4m} = 17.7 nF (3)[/tex]
c)
From (3) we can solve for Q as follows:[tex]Q = C* V = 17.7 nF * 9.0 V = 159.3 nC (4)[/tex]
a) Electric field between the plates, E = 4.5*10⁴ V/m
b) Capacitance of the capacitor, C= 17.7 nF
c) Magnitude of the charge, Q = 159. 3 nC
a) Calculation of Electric field:It is the electrostatic force per unit charge, and since the potential difference between plates is just the work done by the field, divided by the charge, assuming a uniform electric field, if V is the potential difference between plates, and d is the separation between plates, the electric field can be expressed as follows:
[tex]E=\frac{V}{d} \\\\E=\frac{90V}{2*10^{-4}m} \\\\E=4.5*10e4V/m[/tex]
b) Calculation for Capacitance:For a parallel-plate capacitor, It is the quotient between the charge on one of the plates and the potential difference between them, and assuming a uniform surface charge density σ, we get:
[tex]Q=\sigma*A[/tex]
On comparing equation 1 and 2:
[tex]C=\frac{Q}{V}\\\\C=\frac{\sigma*A}{E*d}\\\\\\C=\frac{\sigma*A}{\frac{\sigma}{E_0}*d}\\\\C=\frac{8.85e^{-12}F/m-0.4m^2}{2e-4m}\\\\C=17.7nF\\\\[/tex]
c) Calculation for magnitude of the charge:From equation 3:
[tex]Q=C*V\\\\Q=17.7*9.0\\\\Q=159.3nC\\[/tex]
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what is ice wedging?(pls answer now)
Answer:
When the cold weather fills hard surfaces with water, it causes it to freeze and expand, causing cracks in the surface.
Consider a ball thrown at an angle of 200 above the horizontal and another ball thrown at 200 below the horizontal. Both balls thrown with the same initial speed of 20 m/s from the top of the Science Center. Draw the motion diagram for both cases indicating the velocity and acceleration vectors. Explain the physics of these two situations and calculate the time taken for the balls to reach the ground.
A small uniform disk and a small uniform sphere are released simultaneously at the top of a high inclined plane, and they roll down without slipping. Which one will reach the bottom first?A) the one of smallest diameter B) the one of greatest mass C) the disk D) the sphere E) They will reach the bottom at the same time.
Answer:
(D) the sphere
Explanation:
The bodies given are Disk and Solid sphere (uniform sphere)
Moment of inertia of the bodies are
I(disk) = [tex]\frac{MR^2}{2}[/tex]
I(sphere) = [tex]\frac{2MR^2}{5}[/tex]
Since the moment of inertia of sphere is less than that of disk, therefore sphere will reach the bottom first.
a pillow is thrown downward
Answer:
Is that the question?
Explanation:
What is the force required to accelerate 1 kilogram of mass at 1 meter per second per second.
1 Newton
1 pound
1 kilometer
1 gram
Answer:
it's answer is 1 newton
Please give an explanation.
Thank you.
Isothermal means constant temperature. On a P-V diagram, this appears as a curve.
Constant volume of course appears as a vertical line.
Work done BY an ideal gas at constant pressure is W = PΔV.
Work done BY an ideal gas at constant temperature is:
W = nRT ln(Vf / Vi)
W = nRT ln(Pi / Pf)
Heat added to an ideal gas at constant volume is Q = (Cᵥ/R) VΔP.
For a monotomic gas, Cᵥ = 3R/2.
For a diatomic gas, Cᵥ = 5R/2.
Change in internal energy equals heat added to the gas minus the work done BY the gas.
ΔE = Q − W
For an ideal gas, if the temperature is constant, ΔE = 0.
Process AAt state 1, the pressure is 94.0 kPa and the volume is 4.0 L. From ideal gas law:
PV = nRT
(94.0 kPa) (4.0 L) = nRT
nRT = 376 J
At state 2, the volume triples to 12.0 L. The work done is:
W = nRT ln(Vf / Vi)
W = (376 J) ln(12 / 4)
W = 413 J
The process is isothermal, so ΔE = 0 J. Therefore, Q = 413 J.
The new pressure is:
P₁ V₁ = P₂ V₂
(94.0 kPa) (4.0 L) = P₂ (12.0 L)
P₂ = 31.3 kPa
Process BAt state 3, the volume is constant at 12.0 L, and the pressure rises back to 94.0 kPa. Since there's no change in volume, W = 0 J. The heat added is:
Q = (Cᵥ/R) VΔP
Q = (3/2) (12.0 L) (94.0 kPa − 31.3 kPa)
Q = 1130 J
So ΔE = Q − W = 1130 J.
Process CFrom ideal gas law:
PV = nRT
(94.0 kPa) (12.0 L) = nRT
nRT = 1128 J
At state 4, the volume returns to 4.0 L. The work done is:
W = nRT ln(Vf / Vi)
W = (1128 J) ln(4 / 12)
W = -1240 J
The process is isothermal, so ΔE = 0 J. Therefore, Q = -1240 J.
The new pressure is:
P₃ V₃ = P₄ V₄
(94.0 kPa) (12.0 L) = P₄ (3.0 L)
P₄ = 376 kPa
Process DFinally back to state 1, the volume is constant at 4.0 L, and the pressure drops back to 94.0 kPa. Again, since there's no change in volume, W = 0 J. The heat added is:
Q = (Cᵥ/R) VΔP
Q = (3/2) (4.0 L) (94.0 kPa − 376 kPa)
Q = -1690 J
So ΔE = Q − W = -1690 J.
Entire CycleFor the entire cycle:
Q = 413 J + 1130 J − 1240 J − 1690 J = -1390 J
W = 413 J + 0 J − 1240 J + 0 J = -827 J
ΔE = 0 J + 1130 J + 0 J − 1690 J = -560 J
A student makes the following claim:
The energy of electromagnetic waves increases with decreasing wavelength.
Which of the following statements support this claim?
O A. Dental patients need to wear lead aprons to protect themselves from X-rays but do not wear
protection from flashlights.
B. Both radio waves and gamma rays are invisible to human eyes.
C. Ultraviolet radiation causes sunburn but radio waves do not.
D. Microwaves are used for communication.
E. Gamma rays are used to kill cancer cells, but microwaves have no known effect on cancer
cells.
Answer:
A, C, E
Explanation:
I put this and got it right.
ne student rubs a balloon against his hair several times. Another student passes a comb through her hair several times. The students place the comb near the balloon and observe that the comb repels the balloon. Which is the most likely reason the comb is able to repel the balloon?
A.The balloon has a positive charge and the comb is neutral.
B. The balloon and the comb have the same electrical charge.
C. The balloon has a negative charge and the comb is neutral.
D. The balloon and the comb have opposite electrical charges
Answer:the ballon and the comb have the same electrical charge
Explanation:because I got the answer right
The comb is able to repel the balloon is that the balloon and the comb possess the same electrical charge. Therefore, option (B) is correct.
What is the electrical charge?Electric charge is the physical property of matter that offers it to experience a force when keep in an electric or magnetic field. An electric charge is related to an electric field, and the moving electric charge produced a magnetic field.
The interaction of the charges creates an electromagnetic force and the combination of an electric field and magnetic field is called an electromagnetic field.
When the students rub a balloon and comb against his hair several times static charges are built up on the balloon and the comb. When the students place the comb near the balloon and the comb repels the balloon means that both the comb and the balloon possess the same type of electrical charges.
Therefore, the balloon and the comb acquired the same electrical charge.
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Dillan rolls a rubber band ball off a desk. If the desk is 0.9 m tall, and the ball lands 2.5 m away, what was the horizontal velocity of the rubber band ball as it went off the table?
Answer: 6.25 m/s
explanation: remember an easir way to solve problems like this is to have a horizontal side (x) and a vertical side (y) and on each side always set up for initial speed, average speed, final speed, distance, time, and acceleration.
lmk if you need anything else or any more good tips yk