Which of the following is a physical change?
sawing a piece of wood in half
O burning a piece of wood
O a copper statue turning from red to green
Orust forming on an iron fence
Answer:
I think its 'sawing a piece of wood in half'
Explanation:
sry if its wrong
the only state of matter that is not a fluid is
Answer:
maybe the answer is solid state
Find the charge on the capacitor in an LRC-series circuit at t = 0.03 s when L = 0.05 h, R = 6 Ω, C = 0.005 f, E(t) = 0 V, q(0) = 4 C, and i(0) = 0 A. (Round your answer to four decimal places.)
Determine the first time at which the charge on the capacitor is equal to zero. (Round your answer to four decimal places.)
The charge on the capacitor in an LRC-series circuit is 2.8907 C.
The first time at which the charge on the capacitor is equal to zero is 0.1409s.
What is capacitor?The capacitor consists of two parallel plates used to store the charge when current flows through it, and provides energy when shuts off.
By the Kirchoff's second law,
Lq'' +Lq' +q/C =E(t)
Where, L =0.05h, R = 6 Ω, C = 0.005 f, E(t) = 0 V, q(0) = 4 C, and i(0) = 0 A.
Equations becomes q''+120q' +4000 =0
The auxiliary equation is m² +120m+4000 =0
Solving this quadratic equation, we have
m =-6± 20i
Then , q(t) = Ae^(-60t)cos 20t + Be^(-60t)sin 20t where, A and B are constants.
At t=0, q(0) =7 =A
and q'(t) = A [ -20e^(-60t)sin 20t - 60e^(-60t)cos 20t ] +B [ 20e^(-60t)cos 20t - 60e^(-60t)sin 20t ]
So, i(0)= q'(0) =0 =-60A +20 B
Putting the value of A=7 above, we have B =21.
So, q(t) = 7e^(-60t)cos 20t + 21e^(-60t)sin 20t
The charge on the capacitor at time t =0.015
q(0.015) = 2.8907 C
Thus the charge on capacitor is 2.8907 C.
q(t) = 7e^(-60t)cos 20t + 21e^(-60t)sin 20t =0
Solve for t, we get
e^(-60t)cos 20t + 3e^(-60t)sin 20t\
-1/3 = sin 20t /cos20t
t =1/20 arctan(-1/3)
As, arctan is defined within -90 to +90,
So, 20t = -0.3218 +π =2.8197
t =0.1409s
Thus the first time at which the charge is zero is 0.1409s.
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Before Schwarzschild, the understanding of relativity to gravitational force was unknown.
t or f
Answer:
False
Explanation:
Help
Light helps you in so many ways. But, if it is not used properly, it can also be harmful to you. How can you use light safely? Provide at least five (5) ways how you will protect yourself from light energy.
Conservation efforts have been effective in _______.
a.
increasing the number of endangered species
b.
reducing all the negative impacts of human activity
c.
preserving wildlife habitats
d.
all of the above
Answer:
The answer is D. All of the above.
Explanation:
All of these were efforts and been effective.
Answer:
c
Explanation:
The magnetic field lines of a bar magnet spread out from the
A. north end to the south end.
B. south end to the north end.
C. edges to the center.
D. center to the edges.
Answer:
I think the letter B. But I'm not sure pero I try mo Lang po baka Yan po ang tamang sagot kac Yan po Yung nilagay na sagot saakin e Kaya try mo Lang po
BRAINLIEST IF ITS CORRECT HEPL
Answer: C.
Explanation: They describe the direction of the magnetic force on a north monopole at any given position.
which vector has an x component with a length of 3?
Answer:
A) b.
Explanation:
all the details are in the attached picture.
The magnitudes of the electric potential and of the electrostatic force depend on which factors? O
A. Mass and distance O
B. Distance and amount of charge O
C. Density and amount of charge O
D. Mass and amount of charge
Answer:
Density and amount of charge O
What kind of object are the light rays interacting with in the model below?
Convex mirror
Convex lens
Concave mirror
Concave lens
Answer:
Concave lens
.............
When the ultrasound beam strikes the surface at or nearly at right angles, the fraction of sound energy that is reflected (R) at the interface between two materials of acoustic impedance Z1 and Z2, respectively, is given by:
Explanation:
the expression of x= -4t+2t^2 where x is displecement?Please help!! Look at pic
Answer:
Explanation:
Voltage and Current relation is given by V=IR
I=9A
R=4Ohm
V=IR
V=9x4=36Volts
Resistance = 4 Ohm
Current = 9 Ampere
Voltage = 36 Volts
a car weighting, 14500 N skids on ice, which has a kinetic coefficient of friction 0.2. It then hits a patch of dry road area which has a Kinetic coefficient of friction of 0.8. What is the change in friction force experienced by the car?
The change in friction force experienced by the car is
What is friction?The friction is caused between two uneven contacting surfaces.
When car is on ice, the friction force is
f = μ N
f₁ = 0.2 x 14500 = 2900N
When the car is on dry road, the friction force is
f₂ = 0.8 x 14500 =11,600 N
The change in friction force =11600 - 2900 = 8700N
Thus, the change in friction force experienced by the car is 8700N.
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Vhat are you looking for when you research a potential employer?
personal information about the managers
company history
related industry news
what its product or service is
An object with a mass of 10 kg is
dropped at the same time as an object with a mass of 100 kg. Assuming both objects are in free fall, explain how they will fall in comparison to one another.
Answer:
See below
Explanation:
They will fall at the same speed .....they will stay together if we ignore air friction
What is the energy of the photon emitted when an electron in a mercury atom drops from energy level f to energy level b?
The energy emitted by a photon when it falls from level f to energy level b is 2.84 eV.
Energy of photon at level f and level b
The energy of a photon at level F is given as -268 eV and the energy photon at level b is given as -5.52 eV.
Energy emitted by a photon when it falls from level f to energy level b is calculated as follows;
ΔE = -2.68 eV - (-5.52 eV)
ΔE = -2.68 eV + 5.52 eV
ΔE = 2.84 eV
Thus, the energy emitted by a photon when it falls from level f to energy level b is 2.84 eV.
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when an Earthquake occurs energy radiates in all direction from its source called the
Answer:
[tex]\huge\boxed{\sf Focus}[/tex]
Explanation:
Focus:The point at which Earthquake occurs is called Focus.It is also called hypocenter.Epicenter:Epicenter is the point on the Earth surface which is just above the focus.Most of the times, epicenter is confused with focus. However, epicenter lies on the Earth surface and focus is the exact point from where the Earthquake originates.
[tex]\rule[225]{225}{2}[/tex]
A particle is in its state of uniform circular motion. prove that its projection along one of its diameter executes simple harmonic motion.
x = R Cos wt, if x = R at t = 0
Uniform circular motion means that w is a constant.Then v = dx/dt = Rw Sinwt
a = d²x/dt² = - Rw² Cos wt = -w² x
Hence its motion is a SHMcalculate the work done 36 kg boxes lifted onto a shelf 1.5 m high
Answer:
529.2 joules
Explanation:
Work done = force x distance = mass x gravity x distance
= 36x9.8 x1.5 =529.2 joules
The horizontal surface on which the block slides is frictionless. The speed of the block before it touches the spring is 5.0 m/s. How fast is the block moving at the instant the spring has been compressed 15 cm? The spring constant k = 2000 N/m.
The block moving at instant the spring is compressed 15cm is √[(25m - 45)/m]
What is conservation of energy principle?When there is no external force acting on the system, the total mechanical energy remains conserved.
K.E i = K.E f + SPE
1/2 mu² =1/2 mv² + 1/2 kx²
Substitute u = 5m/s, k =2000N.m and x =0.15m, we get the final velocity
1/2 mu² =1/2 mv² + 1/2 kx²
v =√[(25m - 45)/m]
Thus, the block moving at the instant the spring has been compressed 15 cm is √[(25m - 45)/m]
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The Venus flytrap is known for which of these behaviors?
closing its flower buds at night
snapping a leaf shut around an insect
closing its leaves when touched by a finger
screeching when in danger
.......................................
.
Explanation:
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A metallic axle with a diameter of 20mm has to be fitted into a wheel which has a circular hole at its center with diameter of 18.5mm
The coefficient of linear expansion of the metal at the given length is determined as 3.75 x 10⁻⁴/⁰C.
Coefficient of linear expansion of the metalThe coeffcient of linear expansion of the metal is calculated as follows;
ΔL = αLΔT
α = ΔL/LΔT
Where;
α is the coefficient of linear expansionΔL is change in length = 20 mm - 18.5 mm = 1.5 mmΔT is change in temperature = 0 - (-200) = 200°CL is the original length = 20 mmα = (1.5)/(20 x 200)
α = 3.75 x 10⁻⁴/⁰C
The complete question is below:
A metallic axle with a diameter of 20mm has to be fitted into a wheel which has a circular hole at its center with diameter of 18.5mm. To fit the axle into the hole, the axle is dipped into liquid nitrogen at a temperature of -200°C. Calculate the coefficient of linear expansion of the metal.
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A copper atom has an atomic number of 29 and an atomic mass of 64. What
is the structure of this atom?
OA. It has a central nucleus composed of 29 protons and 64 neutrons,
surrounded by an electron cloud containing 29 electrons.
B. It has a central nucleus composed of 29 protons and 35 neutrons,
surrounded by an electron cloud containing 29 electrons.
OC. It has a central nucleus composed of 29 protons and 29 neutrons,
surrounded by an electron cloud containing 35 electrons.
D. It has a central nucleus composed of 35 protons and 29 neutrons,
surrounded by an electron cloud containing 29 electrons.
Answer:
It has a central nucleus composed of 29 protons and 35 neutrons, surrounded by an electron cloud containing 29 electrons
Explanation:
Atoms Composition:
A atom is mainly composed of a centrally-placed nucleus. A nucleus consists of protons and neutrons with a cloud of electrons surrounding the outside. A proton is a nuclear particle having a positive charge equal to that of an electron and a mass more than 1800 times the electron. A neutron is a nuclear particle having a mass almost identical to that of an electron, but no electric charge.Calculation:
Mass number = Proton + Neutron64 = 29 + NeutronCollect like termsNeutron = 64 – 29Neutron = 35a toy car needs a source of energy to move. how could you give gravitational potential energy to a toy car so that it will move when you let it go?
Answer:
wait one second im about to go get some milk im thirsty
Explanation:
do you want any chicken on your salad
As a pan is sitting on a stove it begins to heat up. Eventually it may get hot enough that it glows red, meaning it is radiating electromagnetic waves within the visible portion of the spectrum. What does this situation show us about electromagnetic radiation?
Electromagnetic radiation can only be emitted in the form of visible light.
The hotter an object is, the faster the electromagnetic radiation will travel.
The electromagnetic radiation emitted by an object is not affected by its temperature.
The hotter an object is, the greater the energy of the electromagnetic radiation in emits.
is it second or first law
Answer:
In the first law, an object will not change its motion unless a force acts on it. In the second law, the force on an object is equal to its mass times its acceleration.
Explanation:
pleaseeee help mehhhh
Why is nuclear energy able to be used for practical purposes? the reactions are controlled to regulate energy output. the reactions are uncontrolled for maximum energy output. all of the products are fed back into the reaction to keep it going. all of the products are immediately removed to inhibit more reactions.
Nuclear energy is able to be used for practical purposes because ; ( A ) The reactions are controlled to regulate energy output
Nuclear energy generationNuclear energy is a clean energy source which has a zero-emission, nuclear energy is used to generate electricity/power following a controlled reaction known as fission of uranium atoms to produce heat energy required to drive a turbine to produce electricity
Hence we can conclude that Nuclear energy is able to be used for practical purposes because ; ( A ) The reactions are controlled to regulate energy output.
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Answer:
option A
Explanation: