Answer:
a) Weight of Roommate = 481.4 N
b) μk = 0.34
Explanation:
a)
The force required to move the couch must be equal to the force of friction:
F = frictional force
F = μW
W = F/μ
where,
W = Total Weight of Couch and Roommate
F = Force Required start to move couch = 250 N
μ = coefficient of static friction between couch and floor = 0.43
Therefore,
[tex]W = \frac{250 N}{0.43}\\\\W = 581.4 N[/tex]
So, the total weight is given as:
W = Weight of Couch + Weight of Roommate
Weight of Roommate = W - Weight of Couch
Weight of Roommate = 581.4 N - 100 N
Weight of Roommate = 481.4 N
b)
Now, the force required to keep the couch moving can be given as equal to the kinetic friction force:
F = kinetic friction
F = μk*W
μk = F/W
where,
μk = coefficient of kinetic friction = ?
F = Force required to keep the couch moving = 200 N
Therefore,
μk = 200 N/581.4 N
μk = 0.34
PLEASE HELP! what kind of electricity does electrical heat burners make
Answer:
Electrical to Thermal
Prob. 3: Manifestation of quantum phenomena (total 25 points) (a)-(e) 5 points each.
Please provide some experimental demonstration or explanation of natural observations or characteristics of application which confirm(s) / display(s) the following notion of quantum physics. In either experiments or observation, please attach a brief explanation and justification to your statement.
3-(A) Vibration of molecules can be treated by quantum mechanics using a parabolic potential. In classical cases, we can use mass(es) attached to a spring. In quantum mechanics, energy levels are quantized, unlike classical oscillators. How can you demonstrate that?
3-(B) The ground state energy of classical oscillator is zero, while that of quantum oscillators has finite (zero-point) energy. How can you demonstrate that (not by calculations but by some experiments or observations)?
3-(C) Electrons can have both orbital and spin angular momentum, and associated magnetic moment. There are two spin quantum numbers (+1/2 or -1/2) for an electron. Describe some quantum phenomena or observation which demonstrate(s) that an electron has a spin 1/2.
3-(D) Laser light is a coherent light. Which property of laser depends on this feature? What application is related to the coherence?
3-(E) Quantum particle(s) can tunnel through a potential barrier.
Answer:
3A. This phenomenon can be seen in the discrete emission of the molecules.
3B. The emotion of the atoms is observed, from states high in energy to a state of minimum energy that is stable indefinitely.
3C. When an electron beam passes through an inhomogeneous magnetic field, it is divided into only two beams
3D. This is due to the stimulated emission
3E. The penetration of a potential barrier is observed in the radioactive emission of heavy atoms, where an alpha particle (Helium nucleus)
Explanation:
This problem asks for some experimental explanations of various quantum phenomena.
3A. This phenomenon can be seen in the discrete emission of the molecules.
In the classical explanation all states or energies are allowed, therefore when emitting energy (photons) there should be a continuum, this is not observed
In the correct quantum explanation only some states are allowed, therefore the emission must be discrete, which is observed in the emission or absorption of molecules and atoms
3B. The emotion of the atoms is observed, from states high in energy to a state of minimum energy that is stable indefinitely.
The incorrect classical explanation that if the minimum energy was zero the electrons cannot rotate around the nuclei and the atom collapses, this does not happen
3C. When an electron beam passes through an inhomogeneous magnetic field, it is divided into only two beams, which is evidence of the existence of two discrete states that we call spin, remember that a free electron beam has zero angular momentum.
3D. This is due to the stimulated emission that occurs when a photon passes through the emission zone, causing the atoms to have transitions and these emitted photons have the same initial photon location, the laser beam all photons are in phase and therefore it is coherent .
This is widely used for holographic and interference work
3E. The penetration of a potential barrier is observed in the radioactive emission of heavy atoms, where an alpha particle (Helium nucleus) leaves the atomic nucleus penetrating the barrier since its energy is lower than the nuclear barrier potential.
Answer:
Explanation:
Please provide some experimental demonstration or explanation of natural observations or characteristics of application which confirm(s) / display(s) the. Quantum mechanics is a fundamental theory in physics that provides a description of the physical properties of nature. Quantum mechanics arose gradually from theories to explain observations. By M Arndt · 2009 · Cited by 239 — Wave-particle duality of light: A paradigmatic example for this fact is the dual nature of light that manifests itself in Young's famous double-slit diffraction.
A force of 100 N acts on a body and moves at a distance of 2 m in the direction of the force. How much work has been done?
Answer:
200 joules
Explanation:
work=force×distance
why is it difficult to lift out the bucket form well
because of gravitional pull
2) Two railway tracks are parallel to west east direction. Along one track, train A moves with a speed of 45 m/s from
west to east, while along the second track, train B moves with a speed of 60 m/s from east to west calculate speed of
Bw.rt. A
Answer:
[tex]Relative\ Velocity = 105m/s[/tex]
Explanation:
Given
[tex]V_A = 45m/s[/tex]
[tex]V_B = 60m/s[/tex]
Required
Determine the speed of B w.r.t A
The question implies that, we determine the relative velocity of B w.r.t A
Because both trains are moving towards one another, the required velocity is a [tex]sum\ of\ velocities\ of[/tex] both trains:
This is shown below:
[tex]Relative\ Velocity = V_A + V_B[/tex]
[tex]Relative\ Velocity = 45m/s + 60m/s[/tex]
[tex]Relative\ Velocity = 105m/s[/tex]
Using a scale of 1 cm to represent 10 N, find the size and direction of the resultant of forces of 50 N
and 30 N acting at the angle of 45 O to each other.
Answer:
[tex]74.31\ \text{N}[/tex]
[tex]16.59^{\circ}[/tex]
Explanation:
P = 50 N
Q = 30 N
[tex]\theta[/tex] = Angle between the vectors = [tex]45^{\circ}[/tex]
Resultant is given by
[tex]R=\sqrt{P^2+Q^2+2PQ\cos\theta}\\\Rightarrow R=\sqrt{50^2+30^2+2\times 50\times 30\times \cos45^{\circ}}\\\Rightarrow R=74.31\ \text{N}[/tex]
Angle of resultant
[tex]\phi=\tan^{-1}\dfrac{Q\sin\theta}{P+Q\cos\theta}\\\Rightarrow \phi=\tan^{-1}\dfrac{30\times \sin45^{\circ}}{50+30\cos45^{\circ}}\\\Rightarrow \phi=16.59^{\circ}[/tex]
Magnitude of the resultant is [tex]74.31\ \text{N}[/tex]
Direction of the resultant is [tex]16.59^{\circ}[/tex]
A has a frequency of 300 Hz and a wavelength of 1.10 m. What is the velocity of the wave?
Hello!!
For calculate the Velocity of the wave let's applicate the formula:
[tex]\boxed{V=f*\lambda}[/tex]
[tex]\textbf{Being:}[/tex]
[tex]\sqrt{}[/tex] V = Velocity = ?
[tex]\sqrt{}[/tex] f = Frequency = 300 Hz
[tex]\sqrt{}[/tex] [tex]\lambda[/tex] = Wavelength = 1,1 m
⇒ [tex]\text{Then let's \textbf{replace it according} we information:}[/tex]
[tex]V = 300 \ Hz * 1,1 \ m[/tex]
⇒ [tex]\text{Let's resolve it: }[/tex]
[tex]V = 330 \ m / s[/tex]
[tex]\textbf{Result:}\\\text{The velocity is \textbf{330 meters per second}}[/tex]
Answer:
For calculate the Velocity of the wave let's applicate the formula:
V = Velocity = ?
f = Frequency = 300 Hz
= Wavelength = 1,1 m
⇒
⇒
Explanation:
A 0.60-kg mass at the end of a spring vibrates 3.0 times per second with and amplitude of 0.13m. Determine
(a) The velocity when it passes the equilibrium point,
(b) The velocity when it is 0.10 m from equilibrium
(c) The total energy of the system, and
(d) The equation describing the motion of the mass, assuming the x was a maximum at t = 0.
Answer:
a) The velocity when it passes the equilibrium point is [tex]\pm 2.451[/tex] meters per second.
b) The velocity when it is 0.10 meters from equilibrium is [tex]\pm 1.567[/tex] meters per second.
c) The total energy of the system is 1.802 joules.
d) The equation describing the motion of the mass, assuming that initial position is a maximum is [tex]x(t) = 0.13\cdot \sin (18.850\cdot t +0.5\pi)[/tex].
Explanation:
a) If all non-conservative forces can be neglected and spring has no mass, then the mass-spring system exhibits a simple harmonic motion (SHM). The kinematic formula for the position of the system ([tex]x(t)[/tex]), measured in meters, is:
[tex]x(t) = A\cdot \sin(\omega \cdot t +\phi)[/tex] (1)
Where:
[tex]A[/tex] - Amplitude, measured in meters.
[tex]\omega[/tex] - Angular frequency, measured in radians per second.
[tex]t[/tex] - Time, measured in seconds.
[tex]\phi[/tex] - Phase, measured in radians.
The kinematic equation for the velocity formula of the system ([tex]v(t)[/tex]), measured in meters per second, is derived from (1) by deriving it in time:
[tex]v(t) = \omega\cdot A\cdot \cos (\omega\cdot t+\phi)[/tex] (2)
The velocity when it passes the equilibrium point occurs when the cosine function is equal to 1 or -1. Then, that velocity is determined by following formula:
[tex]v = \pm \omega\cdot A[/tex] (3)
The angular frequency is calculated by this expression:
[tex]\omega = 2\pi\cdot f[/tex] (4)
Where [tex]f[/tex] is the frequency, measured in hertz.
If we know that [tex]f = 3\,hz[/tex] and [tex]A = 0.13\,m[/tex], then the velocity when it passes the equilibrium point, which is the maximum and minimum velocities of the mass:
[tex]\omega = 2\pi\cdot (3\,hz)[/tex]
[tex]\omega \approx 18.850\,\frac{rad}{s}[/tex]
[tex]v = \pm \left(18.850\,\frac{rad}{s} \right)\cdot (0.13\,m)[/tex]
[tex]v = \pm 2.451\,\frac{m}{s}[/tex]
The velocity when it passes the equilibrium point is [tex]\pm 2.451[/tex] meters per second.
b) First, we need to determine the spring constant of the system ([tex]k[/tex]), measured in newtons per meter, in terms of the angular frequency ([tex]\omega[/tex]), measured in radians per second, and mass ([tex]m[/tex]), measured in kilograms. That is:
[tex]k = \omega^{2}\cdot m[/tex] (5)
If we know that [tex]\omega \approx 18.850\,\frac{rad}{s}[/tex] and [tex]m = 0.60\,kg[/tex], then the spring constant is:
[tex]k = \left(18.850\,\frac{rad}{s} \right)^{2}\cdot (0.60\,kg)[/tex]
[tex]k = 213.194\,\frac{N}{m}[/tex]
Lastly, we determine the velocity when the mass is 0.10 meters from equilibrium by the Principle of Energy Conservation:
[tex]U_{k} + K = K_{max}[/tex] (6)
[tex]\frac{1}{2}\cdot k\cdot x^{2} + \frac{1}{2}\cdot m\cdot v^{2} = \frac{1}{2}\cdot m\cdot v_{max}^{2}[/tex] (7)
Where:
[tex]U_{k}[/tex] - Current elastic potential energy, measured in joules.
[tex]K[/tex] - Current translational kinetic energy, measured in joules.
[tex]K_{max}[/tex] - Maximum translational kinetic energy, measured in joules.
[tex]v[/tex] - Current velocity of the system, measured in meters per second.
[tex]m[/tex] - Mass, measured in kilograms.
[tex]v_{max}[/tex] - Maximum velocity of the system, measured in meters per second.
If we know that [tex]k = 213.194\,\frac{N}{m}[/tex], [tex]x = 0.10\,m[/tex], [tex]m = 0.60\,kg[/tex] and [tex]v_{max} = \pm 2.451\,\frac{m}{s}[/tex], then the velocity of the mass-spring system is:
[tex]\frac{k}{m} \cdot x^{2} + v^{2} = v_{max}^{2}[/tex]
[tex]v^{2} = v_{max}^{2}-\frac{k}{m}\cdot x^{2}[/tex]
[tex]v = \sqrt{v_{max}^{2}-\frac{k\cdot x^{2}}{m} }[/tex] (8)
[tex]v = \sqrt{\left(\pm 2.451\,\frac{m}{s} \right)^{2}-\frac{\left(213.194\,\frac{N}{m} \right)\cdot (0.10\,m)^{2}}{0.60\,kg} }[/tex]
[tex]v \approx \pm 1.567\,\frac{m}{s}[/tex]
The velocity when it is 0.10 meters from equilibrium is [tex]\pm 1.567[/tex] meters per second.
c) The total energy of the system ([tex]E[/tex]), measured in joules, can be determined by the following expression derived from the Principle of Energy Conservation:
[tex]E = \frac{1}{2}\cdot m\cdot v_{max}^{2}[/tex] (9)
If we know that [tex]m = 0.60\,kg[/tex] and [tex]v_{max} = \pm 2.451\,\frac{m}{s}[/tex], then the total energy of the system is:
[tex]E = \frac{1}{2}\cdot (0.60\,kg)\cdot \left(\pm 2.451\,\frac{m}{s}\right)^{2}[/tex]
[tex]E = 1.802\,J[/tex]
The total energy of the system is 1.802 joules.
d) Given that initial position of the mass-spring system is a maximum, then we conclude that the equation of motion has the following parameters: ([tex]A = 0.13\,m[/tex], [tex]\omega \approx 18.850\,\frac{rad}{s}[/tex] and [tex]\phi = 0.5\pi\,rad[/tex])
From (1) we obtain the resulting formula:
[tex]x(t) = 0.13\cdot \sin (18.850\cdot t +0.5\pi)[/tex] (10)
The equation describing the motion of the mass, assuming that initial position is a maximum is [tex]x(t) = 0.13\cdot \sin (18.850\cdot t +0.5\pi)[/tex].
Can you help with this question please
Answer:
First answer to the first question is Two people pulling a rope with the same force in a opposite direction. The other one would be 2.72N
Explanation:
Hope this helps you :)
Which statement accurately describes thermal energy?
Answer:
here are the options.
Answer:
the energy that is associated with temperature or D
Explanation:
Hope this helps
Using a light microscope, a student identified the following characteristics of four organisms found in a sample of pond water. Based on the observations of the student,
which organisms most likely belong to the taxonomic group for bacteria?
Pond-Water Organisms
Organism 1 Single-celled, nucleus, large vacuole
Organism 2 Single-celled, no nucleus, cell wall
Organism 3 Single-celled, no nucleus
Organism 4 Single-celled, nucleus
Organism 1 and 4
Organism 1 and 2
Organism 3 and 4
Organism 2 and 3
Answer:
Organisms 2 and 3
Explanation:
Which of the following is true for valence electrons?
Valence electrons are always located in the outer most energy level.
Valence electrons are found only in radioactive isotopes.
Valence electrons are always located in the innermost energy level
Valence electrons are found only in negatively charged ions.
Answer:
Valence electrons are always located in the outer most energy level.
Explanation:
Valence electrons are the ones that are involved in chemical bonds. In order to take part in a chemical bonding, the outermost/valence electron needs to be involved. Thus, the answer is Valence electrons are always located in the outer most energy level.
Can hurricanes produce tornadoes
Answer:
No
Explanation:
Answer:
No
Explanation:
Tornadoes are usally produced in the Midwest regions. Hurricanes are made with water, not clouds. So, no, hurricanes cannot produce tornadoes.
vector of magnitude 15 is added to a vector of magnitude 25. The magnitude of this sum
might be:
A. Zero
B.5
C.9
0 15
E.4
and how ?
Explanation:
Given that,
Magnitude of vector A, |A| = 15
Magnitude of vector B, |B| = 25
We need to find the magnitude of this sum.
The maximum sum of the resultant vector,
[tex]R_{max}=|A_1|+|A_2|\\\\=15+25\\\\=45[/tex]
The minimum sum of the resultant vector,
[tex]R_{min}=|A_1|-|A_2|\\\\=15-25\\\\=-10[/tex]
So, the magnitude of this sum either 45 or -10.
Water can form large dewdrops in nature how would droplets made of vegetable oil instead of water be different
Answer:d
Explanation: oil would form droplets but only tiny ones because it’s surface tension is lower than that of water
Both water and vegetable oil would made droplets but Oil would form only very tiny droplets because its surface tension is lower than that of water.
What is surface tension?Surface tension is the propensity for liquid surfaces that are at rest to condense into the smallest surface area. Razor blades and insects (like water striders), which have a higher density than water, can float on the surface of the water without even becoming partially buried because to surface tension.
Surface tension at liquid-air contacts originates from the liquid molecules' stronger attraction to one another due to cohesion than to the air molecules (due to adhesion).
As the surface tension of the oil is lower than that of water, it forms droplets will smaller size.
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Define a rotation of the earth answer fast
Answer:
here u go
Explanation:
Earth's rotation is the rotation of planet Earth around its own axis. Earth rotates eastward, in prograde motion. As viewed from the north pole star Polaris, Earth turns counterclockwise.
Number 1a and b and number 2(everything)
Answer:
Explanation:
The density of a substance is the ratio of its mass to its volume. Its unit of measurement is kg[tex]m^{-3}[/tex].
i.e density, ρ = [tex]\frac{mass}{volume}[/tex]
1a. To determine the density of the acetic acid, Rachael needs to know the mass and volume of the acid.
i. Measure the mass of the given beaker using the mass balance.
ii. Transfer the acetic acid into the beaker, and measure the new mass using the mass balance.
iii. Subtract the mass of the beaker from the new mass to determine the mass of the acetic acid.
iv. Measure the volume of the acid on the scale of the beaker.
v. Divide the value of the mass by its volume to determine its density of the acetic acid.
b. Given that the density is 1.05 g/[tex]cm^{3}[/tex], and volume is 200 [tex]cm^{3}[/tex].
Then,
density = [tex]\frac{mass}{volume}[/tex]
1.05 = [tex]\frac{mass}{200}[/tex]
mass = 1.05 x 200
= 210 g
mass = 210 g
2. Length of titanium = 0.40 m
Area of titanium = 0.05 [tex]m^{2}[/tex]
mass = 90.0 kg
density = [tex]\frac{mass}{volume}[/tex]
But,
volume = area x length
= 0.05 x 0.4
= 0.02 [tex]m^{3}[/tex]
density of titanium = [tex]\frac{90}{0.02}[/tex]
= 4500 kg[tex]m^{-3}[/tex]
Good conductors have:
Question 9 options:
A) current moves easily
B) conserves energy-easy for electrons to move
C) all of the above
D) low resistance
Answer:
[tex]\boxed{\boxed{\sf all \ of \ the \ above }}[/tex]
MORE TO KNOW Materials that easily allow the current to pass through it are called Good conductor Materials that can pass the current but not as much as good conductor are called poor conductor Materials that did not allow the current to pass through are called Insulator Current is produced when a group of electrons move through a conductor SI unit of Current is Ampere Ammeter is an instrument that measures Electric current SI unit of charge is Coulomb ( equal to 6 × 10 power 18 electrons )The electric difference between the points make electrons move This difference is called Potential differenceIt is measure by an instrument called VoltmeterGood conductors have: current moves easily, low resistance, conserves energy-easy for electrons to move. Hence, Option (C) is correct.
What is conductor?Materials that easily permit the flow of electricity are referred to be electrical conductors. Conductivity is the quality of conductors that enables them to conduct electricity.
Electric current is the name given to the movement of electrons through conductor. Voltage is the amount of power necessary to cause that current to flow through the conductor.
Such an element receives a charge that is dispersed along its entire surface, causing the electrons inside the element to migrate. Charges are transferred to an electrical conductor, and they disperse until the minimal force of repulsion between electrons in locations of excess electrons. Such an item transfers its charge to another conductor when it comes into contact with it, reducing the overall repulsion caused by charge in the process.
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list at least three examples of circular motion
Answer:
When an object moves with a constant speed in a circular path, then its motion is called as Circular motion.
Examples of Uniform Circular Motion :--
The moon moves in uniform circular motion around the earth.
A stoned tied to a thread and rotated in circular motion.
An athlete running on a circular track.
A satellite revolving around Earth.
A storm front moves in and Rachel and Pam notice the column of mercury in the barometer rises only to 736 mm. Assume the density of mercury is 13, 000 kg/m 3
(a) What is the change in air pressure?
(b) What if their barometer was filled with water instead of mercury, how high does the column rise? Density of water = 1000 kg/m
Answer:
a
[tex]\Delta P = 7558.6 \ Pa[/tex]
b
[tex]h_1 = 10 \ m[/tex]
Explanation:
From the question we are told that
The position of the column of mercury in the barometer is [tex]h = 736 \ mm = 0.76 \ m[/tex]\
The density of mercury is [tex]\rho = 13,000 \ kg / m^3[/tex]
Generally the pressure of the atmosphere at that column is mathematically represented as
[tex]P = \rho * g * h[/tex]
=> [tex]P =13 000 * 9.8 * 0.736[/tex]
=> [tex]P = 93766.4 \ Pa[/tex]
Generally the atmospheric pressure at sea level (Generally the pressure before the change in level of the mercury column) is [tex]P_a = 101325 \ Pa[/tex]
Generally the change in air pressure is mathematically represented as
[tex]\Delta P = P_a - P[/tex]
=> [tex]\Delta P = 101325 - 93766.4[/tex]
=> [tex]\Delta P = 7558.6 \ Pa[/tex]
Generally the height which the column will rise to is mathematically evaluated as
[tex]h_1 = \frac{P}{ \rho_w * g }[/tex]
Here [tex]\rho_w[/tex] is the density of water with value [tex]\rho_w = 1000 \ kg/m^3[/tex]
So
[tex]h_1 = \frac{ 93766.4}{ 1000 * 9.8 }[/tex]
=> [tex]h_1 = 10 \ m[/tex]
Secretariat is known as the horse with the fastest run in the Kentucky Derby. If Secretariat's record 1.25 mi run lasted 1 minute 59.2 seconds, what was his average speed in m/s
Answer:
v = 16.87 m/s
Explanation:
Given that,
Distance, d = 1.25 miles
d = 2011.68 m
Time, t = 1 minute 59.2 seconds
= 60 s + 59.2 s
= 119.2 s
We need to find the average speed of the horse. It is given by total distance covered divided by total time.
[tex]v=\dfrac{2011.68 \ m}{119.2\ s}\\\\=16.87\ m/s[/tex]
So, his average speed is 16.87 m/s.
Explain how polarization of a cell increases the cell's internal resistance.
(2
2.
Answer:
Explanation: The chemical action that occurs in the cell while the current is flowing causes hydrogen bubbles to form on the surface of the anode. This action is called POLARIZATION. Some hydrogen bubbles rise to the surface of the electrolyte and escape into the air, some remain on the surface of the anode. If enough bubbles remain around the anode, the bubbles form a barrier that increases internal resistance. When the internal resistance of the cell increases, the output current is decreased and the voltage of the cell also decreases.
A cell that is heavily polarized has no useful output. There are several methods to prevent polarization or to depolarize the cell.
One method uses a vent on the cell to permit the hydrogen to escape into the air. A disadvantage of this method is that hydrogen is not available to reform into the electrolyte during recharging. This problem is solved by adding water to the electrolyte, such as in an automobile battery. A second method is to use material that is rich in oxygen, such as manganese dioxide, which supplies free oxygen to combine with the hydrogen and form water.
A third method is to use a material that will absorb the hydrogen, such as calcium. The calcium releases hydrogen during the charging process. All three methods remove enough hydrogen so that the cell is practically free from polarization.
LOCAL ACTION
When the external circuit is removed, the current ceases to flow, and, theoretically, all chemical action within the cell stops. However, commercial zinc contains many impurities, such as iron, carbon, lead, and arsenic. These impurities form many small electrical cells within the zinc electrode in which current flows between the zinc and its impurities. Thus, the chemical action continues even though the cell itself is not connected to a load.
Local action may be prevented by using pure zinc (which is not practical), by coating the zinc with mercury, or by adding a small percentage of mercury to the zinc during the manufacturing process. The treatment of the zinc with mercury is called amalgamating (mixing) the zinc. Since mercury is many times heavier than an equal volume of water, small particles of impurities weighing less than mercury will float to the surface of the mercury. The removal of these impurities from the zinc prevents local action. The mercury is not readily acted upon by the acid. When the cell is delivering current to a load, the mercury continues to act on the impurities in the zinc. This causes the impurities to leave the surface of the zinc electrode and float to the surface of the mercury. This process greatly increases the storage life of the cell.
Can I get help on this question please I don’t understand
Answer:
A
Explanation:
Weight = 55 * 9.8 = 539 N
Scale = 686 N
Since the scale reading is larger than the lady’s weight, the elevator must be accelerating as it moves upward.
Net upward force = 686 – 539 = 147 N
147 = 55 * a
a = 147 ÷ 55
The acceleration is approximately 2.67 m/s^2.
help plz i need it in the next 30 mins
Answer:
i think it's d
Explanation:
Answer:
D
Explanation:
i feel like this one is it
a machine
of efficiency of 70% is used to raise
a body of
mass 80 kg through
a vertical distance of 3m in
40 seconds. Calculate the power input. (Take g = 10 m/s²)
Answer:
Power_input = 85.71 [W]
Explanation:
To be able to solve this problem we must first find the work done. Work is defined as the product of force by distance.
[tex]W = F*d[/tex]
where:
W = work [J] (units of Joules)
F = force [N] (units of Newton)
d = distance [m]
We need to bear in mind that the force can be calculated by multiplying the mass by the gravity acceleration.
Now replacing:
[tex]W = (80*10)*3\\W = 2400 [J][/tex]
Power is defined as the work done over a certain time. In this way by means of the following formula, we can calculate the required power.
[tex]P=\frac{W}{t}[/tex]
where:
P = power [W] (units of watts)
W = work [J]
t = time = 40 [s]
[tex]P = 2400/40\\P = 60 [W][/tex]
The calculated power is the required power. Now as we have the efficiency of the machine, we can calculate the power that is introduced, to be able to do that work.
[tex]Effic=0.7\\Effic=P_{required}/P_{introduced}\\P_{introduced}=60/0.7\\P_{introduced}=85.71[W][/tex]
A fruit bat falls from the roof of a cave. We know that her potential energy was
600 J, and that the roof of the cave was 12.8 meters high. What is her velocity
when she hits the ground?
Answer:
v = 15.65 m/s
Explanation:
We use conservation of mechanical energy between initial (i) and final (f) states:
Pi + KEi = Pf + KEf
At the top of the cave at the instant the bat starts to fall, there is only potential energy since the bat's velocity is zero.
Pi = m g h = 600 J
and the KEi = 0 J (no velocity)
Knowing the height of the cave's roof (12.8 m) , we can find the mass of the bat:
m = 600 J / (g 12.5) = 4.9 kg
Using conservation of mechanical energy, the final state is:
Pf + KEf = 600 J
with Pf = 0 (just touching the ground)
KEf= 1/2 4.9 (v^2)
and we solve for the velocity:
600 J = 0 + 1/2 4.9 (v^2)
v^2 = 600 * 2 / 4.9 = 244.9
v = 15.65 m/s
How do the permanent magnets in an electric generator induce a current in a loop of wire that is moving between them?
A. The magnets cause charged particles within the wire to move as the poles of the magnets switch.
B. The moving electrons flow from the permanent magnets into the loop of wire.
C. The magnetic field of each magnet attracts the metal in the moving loop of wire.
D. The magnetic field between the magnets causes the charged particles within the wire to move.
Correct answer is D
The magnetic field between the magnets causes the charged particles within the wire to move.
According Faraday's law of electromagnetic induction, whenever their is a relative motion of a conductor is magnetic field, an emf will be induced in the conductor and the strength of the induced emf is directly proportional to the rate of change of magnetic flux linking the circuit.
The motion of the electrons is due to magnetic field created by the permanent magnet of the electric generator.
Thus, the magnetic field between the magnets causes the charged particles within the wire to move.
Learn more about about Faraday's law here: https://brainly.com/question/4418412
2. Two identical spheres having charges Q and -
2Q experience a force F at a certain distance
If the spheres are kept in contact and then
placed at same initial distance, the force
between them will be
force between the two charges (+q1 and +q2),if they are at a distance 'a' is
F1=1/4pieEo q1q2/d^2................ (1)
when the metal spheres are in contact the charge flow from one sphere to another till both the sides acquires the same charge. here q1 and q2 are of same sign,hence after contact each sphere will have a charge
[tex] \binom{q1 + q2 }{2} [/tex]
now,the force between them,
f2=1/4pieEo
(q1+q2/2)^2/d^2
from eq (1)and eq (2)
f2=f1 (q1+q2)^2/4q1q2
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an effort force 40n is applied to a screwdriver to pry the lid off of a can of pain. the screwdriver applies 100n of force to the lid. what is the MA of the screwdriver?
Answer:
MA = 2.5
Explanation:
Given that,
Effort force applied to a screwdriver to pry the lid off of a can= 40 N
The screwdriver applies 100n of force to the lid = 100 N
We need to find the mechanical advantage of the screwdriver. Mechanical advantage of a machine is given by the ratio of load to the effort.
m = load/effort
= 100/40
= 2.5
Hence, the MA of the screwdriver is 2.5