Explain how an electrical current is produced.
Answer:electric current can be generated by moving a metal wire through a magnetic field .electric current can also be produced by batteries
Explanation:
electric current can be generated by moving a metal wire through a magnetic field.this method is applicable in electric generators.
Electric current can also be generated by connecting metal wires to batteries.
Describe at least two different objects that you think are magnetic and why do you think this objects are magnetic
Answer:
Magnetic letters Screws and bolts
Explanation:Magnetic letters have to be magnetic so they can stick to things like walls and fridges. Screws and bolts are magnetic becaus they become easier to to screw onto things since the tool that you use to screw it in is also magnetic.
Answer:
File cabins and nails/screw,
Explanation:
Because they are ferromagnetic this means that they can be magnetized. Magnetic objects are made of metal and metals do attract magnet.
plzzz help will mark the brainliest
An athlete is working out in the weight room. He steadily holds 50 kilograms above his head for 10 seconds. Which statement is true about this situation?
Answer:
Answer: the true statement form the given statements is “the athletes is not doing any work because he does not move weight”
Explanation:
The athlete isn’t doing any work because he doesn’t move the weight is the correct statement.
What is Work? Work is the energy transferred to or from an object via the application of force along a displacement.Work = Force x Displacement.How to solve this Problem?The weight of an object given is 50kgsThe time of holding an object given is 10 secondsWe need to justify the statements
Here ,
There is no displacement that means displacement is zero.If displacement is zero then work done will also be zeroHence there is no work done by the athlete
Therefore ,The athlete isn’t doing any work because he doesn’t move the weight is the correct statement
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Dual Nature of Light
Assignment
Active
Explaining the Nature of Light
Why do scientists believe that light is made of streams of
particles?
1) Calculate the equivalent resistance of 2 resistors wired in parallel. The value of the resistors are
4 ohms and 8 ohms.
Explanation:
[tex]r = \: ( { \frac{4 \times 8}{4 + 8} } \\ r= \: ohm[/tex]2.67
Answer:2 2/3 ohms
Explanation:
equivalent resistance=R
r1=4 ohms
r2=8 ohms
For parallel connection
1/R=1/(r1) + 1/(r2)
1/R=1/4 + 1/8
1/R=(2x1+1x1)/8
1/R=(2+1)/8
1/R=3/8
Cross multiply
1x8=3xR
8=3R
Divide both sides by 3
8/3=3R/3
8/3=R
R=8/3 or 2 2/3 ohms
"It is impossible to devise a process which may convert heat, extracted from a single
reservoir, entirely into work without leaving any change in the working system”.
Use the Second Law of Thermodynamics to state our inability to utilize the heat contents
of oceans and atmosphere which contains a large amount of heat energy but cannot be
converted into useful mechanical work You may use the concept of heat engine to discuss
this
Answer:
According to the second law of thermodynamics, we are unable to use the heat of the ocean and the atmosphere because we do not have a reservoir that has a temperature lower than the ocean or the atmosphere.
Explanation:
As you already know, the ocean and atmosphere have a lot of thermal energy, however, we are unable to convert this energy into mechanical energy that would be useful for our activities. This can be explained by the second law of thermodynamics, since it states that the presence of two bodies with different temperatures is necessary for it to be possible to transform heat into work.
In this case, to transform the thermal energy of the ocean and the atmosphere into mechanical energy we would need the existence of a thermal motor, which is only possible to be established when there is a body with high thermal energy and a sink, a reservoir, with low thermal energy, which will be the place where the heat will be expelled, to be converted into work. We do not have a reservoir with less thermal energy than the ocean and the atmosphere, so we cannot use their energy.
A three-phase Y-connected four-pole winding is installed in 24 slots on a stator. There are 40 turns of wire in each slot of the windings. All coils in each phase are connected in series. The flux per pole in the machine is 0.060 Wb, and the speed of rotation of the magnetic field is 1800 r/min. (a)What is the frequency of the voltage produced in this winding?(b)What are the resulting phase and terminal voltages of this stator?
Given Information:
Number of slots = 24
Number of turns = 40
Flux per pole = 0.060 Wb
Speed of rotation of magnetic field = 1800 rev/min
Required Information:
a) Frequency = ?
b) Phase and Terminal voltage = ?
Answer:
a) Frequency = 60 Hz
b) Phase voltage = 2560 V
Terminal voltage = 4434 V
Explanation:
(a)What is the frequency of the voltage produced in this winding?
The relation between frequency of the voltage produced and the speed of rotation of magnetic field is given by
[tex]f = \frac{nP}{120}[/tex]
Where n is the speed of rotation of magnetic field and P is the number of poles in the winding.
[tex]f = \frac{1800\times 4}{120}\\\\f = \frac{7200}{120}\\\\f = 60 \: Hz[/tex]
(b)What are the resulting phase and terminal voltages of this stator?
The phase voltage is given by
[tex]E = \sqrt{2} \cdot \pi\cdot N\cdot \phi\cdot f[/tex]
Where N is the number of turns, Ф is the flux per pole and f is the frequency calculated in part a.
[tex]E = \sqrt{2} \cdot \pi\cdot 40\cdot \ 0.060\cdot 60\\\\E = 639.77\\\\E = 640 \:V\\\[/tex]
There are total 24 slots so each phase has 24/3 = 8 slots
We know that the number of poles are 4 so that means each phase has 4 sets of coils.
So the voltage in each phase is
Vp = 4*640
Vp = 2560 V
Since it is a Y-connected machine, The terminal voltage is will be
[tex]V_T = \sqrt{3} V_p\\\\V_T = \sqrt{3} \cdot2560\\\\V_T = 4434 \: V\\\\[/tex]
Visible light travels in air, which has an index of refraction of 1.0. It is incident on plastic which is covered by a coating (such that light hits the coating before the plastic). The coating has an index of refraction of 1.6 and is 0.50 microns thick. The ray reflected off the air-coating interface and the ray reflected off the coating-plastic interface experience interference. What frequencies could the light be
Answer:
λ = 0.64 10⁻⁶ m = 640 nm
Explanation:
The two reflected rays experience constructive interference, if we can see them, so we can one condition for interference, but let's see two phenomena that occur
* A ray when it is reflected by a surface of major spare part index has a phase change of 180º, these passes at the air-plastic interface
* A ray when passing a material with a refractive index changes its wavelength
λ= λ₀ / n
taking into account these facts the condition in constructive interference is
2 n t = (m + ½) λ
λ= 2 n t / (m + ½)
if we suppose that we have the first inference m = 0
λ = 2 1.6 0.5 10⁻⁶ (0 + ½)
λ = 3.2 10⁻⁶ m
this wavelength is in the infrared
suppose an interference of m = 1
λ = 1.6 10⁻⁶ / (1 + 1/2)
λ = 1.06 10-6 m
m = 2
λ = 1.6 10⁻⁶ / (2 + 1.5)
λ = 0.64 10⁻⁶ m
this wavelength corresponds to the visible range (640 nm) orange
A large boulder falls from an underwater ledge and crashes on the floor of the ocean. A pod of dolphins is 800 meters away. Determine how long it takes for the sound of the crash to reach the dolphins.
0.5 sec
0.3 sec
2.3 sec
1.9 sec
Answer:
0.5
Explanation:
Answer:
0.539
Explanation:
A 50 Ohm resistance causes a current of 5 milliamps to flow through a circuit connected to a battery. What is the power in the circuit?
Answer:0.00125 watts
Explanation:
resistance=50 ohms
Current=5 milliamps
Current=5/1000 amps
Current=0.005 amps
Power=(current)^2 x (resistance)
Power=(0.005)^2 x 50
Power=0.000025 x 50
Power=0.00125 watts
Answer:
if a circuit is powered by 100v and has an overall resistance of 50 ohms 2 amps flows through the circuit
Explanation:
1. You are playing with a jump rope that is tied at both ends. You untie one end, hold it taut and wiggle the end up and down sinusoidally with frequency 2.00Hz and amplitude 0.075m. At time t=0, the end has a maximum positive displacement and is instantaneously at rest. Assume no wave bounces back from the far end to change the pattern. What is the equation for the displacement of the wave? What is the displacement at a point 3.00m from the end .
Answer:
[tex]f(x=3.00m)=0.075mcos(\frac{2\pi(2.00Hz)}{v}(3.00m))[/tex]
Explanation:
To find the equation of the wave you use the general equation for a wave, given by:
[tex]f(x)=Acos(k x-\omega t)[/tex]
A: amplitude of the wave = 0.075m
k: wave number
you select a cosine function because for x=0 and t= 0 you get a maximum displacement.
To find the displacement of the wave for x=0 you can consider that the form of the wave is independent of time t.
Then, you calculate k:
[tex]k=\frac{\omega}{v}=\frac{2\pi f}{v}[/tex]
Thus, you need the value of the speed of the wave (you only have the frequency f), in order to calculate f(x), for x=3.00m:
[tex]f(x=3.00m)=0.075mcos(\frac{2\pi(2.00Hz)}{v}(3.00m))[/tex]
Can a moving object have gravitational energy?
Answer:
It is worth noting that the higher the gravitational energy of an object moving downwards, the lower the kinetic energy, and the lower the kinetic energy of an object moving upwards, the higher its gravitational energy.
Gravitational potential energy is acquired by an object when it has been moved against a gravitational field. For example, an object raised above the surface of the Earth will gain energy, which is released if the object is allowed to fall back to the ground.
A chemical reaction occurs. Which of the following would indicate that energy is transformed during the reaction? A. an electrical charge is produced B. heat is produced C. light is produced D. all of these
Answer:
b
Explanation:
A potato and raisins salad has been warmed up to a temperature of 80∘C and let it stand for three minutes. Then one tries a bite. 1) Would the potatoes and raisins be equally warm? Potatoes have a specific heat of 3430 J/(kg⋅∘C). Raisins have a specific heat of 1630 J/(kg⋅∘C).
Answer:
No. Potatoes will be warmer.
Explanation:
[tex]Q=m\times c\times \Delta T[/tex]
where,
Q = heat taken
m = mass of substance
c = specific heat of substance = ?
ΔT = change in temperature
As we are given that the potatoes have a specific heat of 3430 J/(kg⋅∘C) and raisins have a specific heat of 1630 J/(kg⋅∘C). It implies that substance take more heat when higher the value of specific heat i.e more warmer will be the substance. Thus, the potatoes will be more warmer as compared to raisins.
Therefore, No. Potatoes will be warmer.
a girl pushes an 18.15 kg wagon with a force of 3.63 N. what is the acceleration?
A. 0.06 m/s2
B. 5 m/s2
C. 0.2 m/s2
Answer:0.2 m/s^2
Explanation:
mass=18.15kg
Force=3.63N
Acceleration=force ➗ mass
Acceleration=3.63 ➗ 18.15
Acceleration=0.2 m/s^2
A girl pushes a wagon of mass 18.15 kg with a force of 3.63 N, so the acceleration of the wagon will be 0.2 m/s².
What is acceleration?In mechanics, acceleration is the measure of how rapidly an object's velocity changes over time. Accelerations as a vector quantity. An object's acceleration depends on the direction of the net force exerted on it.
A vector quantity, acceleration, is something that has both a magnitude and a direction. As a vector quantity, velocity is also. The ratio of the velocity vector change over a time interval to that interval is the definition of acceleration.
Mass, m =18.15 kg
Force, f = 3.63 N
Force = m × a
a= f / m
a =3.63 / 18.15
a = 0.2 m/s²
Hence, the acceleration of the wagon will be 0.2 m/s².
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Speed is the rate of change of position expressed as____ Traveled per unit of time
Answer:
distance
Explanation:
Speed is the rate of change of position expressed as distance travelled per unit of time
Modern wind turbines generate electricity from wind power. The large, massive blades have a large moment of inertia and carry a great amount of angular momentum when rotating. A wind turbine has a total of 3 blades. Each blade has a mass of m = 5500 kg distributed uniformly along its length and extends a distance r = 44 m from the center of rotation. The turbine rotates with a frequency of f = 13 rpm.
a. Calculate the total moment of inertia of the wind turbine about its axis, in units of kilogram meters squared.
b. Calculate the angular momentum of the wind turbine, in units of kilogram meters squared per second.
Answer:
a)106.48 x 10⁵ kg.m²
b)144.97 x 10⁵ kgm² s⁻¹
Explanation:
a)Given
m = 5500 kg
l = 44 m
Moment of inertia of one blade
[tex]I[/tex]= 1/3 x m l²
where m is mass of the blade
l is length of each blade.
Putting all the required values, moment of inertia of one blade will be
[tex]I[/tex]= 1/3 x 5500 x 44²
[tex]I[/tex]= 35.49 x 10⁵ kg.m²
Moment of inertia of 3 blades
[tex]I[/tex]= 3 x 35.49 x 10⁵ kg.m²
[tex]I[/tex]= 106.48 x 10⁵ kg.m²
b) Angular momentum 'L' is given by
L =[tex]I[/tex] x ω
where,
[tex]I[/tex]= moment of inertia of turbine i.e 106.48 x 10⁵ kg.m²
ω=angular velocity =2π f
f is frequency of rotation of blade i.e 13 rpm
f = 13 rpm=>= 13 / 60 revolution per second
ω = 2π f => 2π x 13 / 60 rad / s
L=[tex]I[/tex] x ω =>106.48 x 10⁵ x 2π x 13 / 60
= 144.97 x 10⁵ kgm² s⁻¹
A pipe branches symmetrically into two legs of length L, and the whole system rotates with angular speed ω around its axis of symmetry. Each branch is inclined at angle α to the axis of rotation. Liquid enters the pipe steadily, with zero angular momentum, at volume flow rate Q. The pipe diameter, D, is much smaller than L. Obtain an expression for the external torque required to turn the pipe. What additional torque would be required to impart angular acceleration ω_ ?
Answer:
Check the explanation
Explanation:
Kindly check the attached images below to see the step by step explanation to the question above.
Question 7
Review
Which particles are not affected by the strong force?
A.
hadrons
B.
protons
C.
neutrons
D
electrons
Submit A
Hide Toolbar
Answer:
Electron
Explanation:
Because electron are not hadrons so electron are not affected by strong force
Particles that can not be affected by strong forces are electrons.
What are electrons?Electrons are the rotating material around the nucleus of an atomic element in orbit.
Atoms have electrostatic energy between their electrons. This force is not broken by a force as strong as nuclear power.
What are strong forces?Strong force is a fundamental interaction of nature that acts between subatomic particles of matter.
There are four basic forces in nature:
Gravity: the gravitational force used between any heavy objects. It has an infinite range.Electrical energy: energy used between electrically charged objects. It can be either attraction or repulsion.Nuclear power: is the magnetic field that responds to the binding of protons and neutrons within the nucleus of an atom. It only works for very short distances.Weak nuclear power: a force that causes nuclear decay. It only works for very short distances.Therefore, particles that are unaffected by strong force are electrons.
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1. A 5 Ohm resistor is connected to a 9 Volt battery. How many Joules of thermal energy are produced in 7 minutes?
2. The current in a flashlight powered by 4.5 Volts is 0.5 A. What is the power delivered to the flashlight?
3. If the flashlight in the previous problem is left on for 3 minutes, how much electric energy is delivered to the bulb?
4. A 50 Ohm resistance causes a current of 5 milliamps to flow through a circuit connected to a battery. What is the power in the circuit?
5. How many Joules of electric energy are delivered to a 60 Watt lightbulb if the bulb is left on for 2.5 hours?
Answer:
Question 1: 189 joules
Question 2: 2.25 watts
Question 3: 405 joules
Question 4: 0.00125 watts
Question 5: 450000 joules
Explanation:
question 1:
Volt=1.5v
Resistance =5 ohms
Time=7 minutes
Time=7 x 60
Time=420 seconds
Current =voltage ➗ resistance
Current =1.5 ➗ 5
Current =0.3 amps
Energy=current x voltage x time
Energy=0.3 x 1.5 x 420
Energy =189 joules
Question 2:
Current =0.5 amps
Voltage =4.5v
Power=current x voltage
Power=0.5 x 4.5
Power=2.25 watts
Question 3:
Current=0.5 amps
Voltage=4.5v
Time =3 minutes
Time =3x60
Time =180 seconds
Energy=current x voltage x time
Energy=0.5 x 4.5 x 180
Energy =405 joules
Question 4:
Resistance=50 ohms
Current =5 milliamps
Current =5/1000
Current =0.005 amps
Power =current x current x resistance
Power=0.005 x 0.005 x 50
Power=0.00125 watts
Question 5:
Power =50 watts
Time=2.5 hour
Time=2.5 x 60 x 60
Time =9000 seconds
Energy=power x time
Energy=50x9000
Energy=450000 joules
Which of the following could possibly be predicted? Earthquakes Landslides Foreshocks Volcanic eruptions
Answer:
Volcanic Eruptions
Explanation:
The volcano can start showing signs that it may be about to explode.
Answer:
Volcanic eruptions.
Explanation:
I had the same question on an assignment and I got it right.
A brick is dropped from a high scaffold. a. What is its velocity after 4.0s ?
b. How far does the brick fall during this time ?
Answer:
A: 1.962
B: 3.924
Explanation:
g = G *M /R^2
g = 9.807*M/R^2 the gravitational constant of ground level on earth is about 9.807
g = 9.807*5lbs/R^2 the average brick is about 5 pounds.
g = 9.807*5*10^2. I'm assuming the height is around ten feet to help you out.
with these numbers plugged in you get an acceleration of 0.4905 a final velocity after 4 seconds 1.962. It's height fallen after 4 seconds is 3.924.
( M = whatever the brick weighs it's not specified in the question)
(R = the distance from the ground or how high the scaffold is)
(hopefully you can just plug your numbers in there hope this helps)
Eclipses of the sun and moon are best explained by which of the following?
The irregular shape of the orbits of Earth and the moon
The rotation of Earth and the moon on their axis
The revolution of Earth and the moon around the sun
The different chemical compositions of the sun and the moon
Answer:
Eclipses of the Sun and Moon are best explained by the revolution of Earth and the Moon around the Sun.
Explanation:
An eclipse is the covering of a star by another celestial body. In everyday language, an eclipse usually means a solar or lunar eclipse.
When the sun, moon and earth are aligned (in this order), the sun is covered by the moon when viewed from a place on earth. The sunlight will then no longer reach the earth. In other words, part of the earth has been eclipsed by the moon. This is referred to as a solar eclipse.
If the earth is between the sun and the moon, and thereby prevents sunlight from reaching the moon, then there is a lunar eclipse. After all, seen from the moon, the earth covers the sun. The moon is then eclipsed by the earth.
A closed container with volume of 7.20 L holds 10.9 g of liquid helium at 3.00 K and enough air to fill the rest of its volume at a pressure of 1.00 atm. The helium then evaporates and the container warms to room temperature (293 K). What is the final pressure inside the container?
Answer:
The final pressure inside the container is 107.7 atm
Explanation:
Given;
volume of the closed container = 7.20 L
mass of liquid helium in the container = 10.9 g
initial temperature of the container = 3.00 K
initial pressure of the container = 1.00 atm.
final temperature of the container = 293 K
Number of moles of He in the container = 10.9 / 4 = 2.725 moles
At 273˚K and 1 atm pressure (STP), the volume of 1 mole of a gas = 22.4 L
Volume of 2.725 moles of He at STP = 2.725 x 22.4 = 61.04 L
Volume of 2.725 moles of He at 3 K and 1 atm = (3/273) x 61.04 = 0.671 L
Thus, volume of He = 0.671 L
Volume of air in the container = 7.2 L – 0.671 L = 6.529 L
Since, the liquid helium evaporated, we only have air left in the container,
thus, final volume of the container, V₂ = 6.529 L
Initial volume of the container, V₁ = 7.20 L
Initial pressure of the in the container, P₁ = 1 atm
initial temperature of the container, T₁ = 3 K
Final temperature of the container, T₂ = 293 K
Final pressure of the container, P₂ = ?
Apply general gas law, in order to estimate P₂
[tex]\frac{P_1V_1}{T_1} = \frac{P_2V_2}{T_2} \\\\P_2 = \frac{P_1V_1T_2}{T_1V_2} \\\\P_2 = \frac{1*7.2*293}{3* 6.529}\\\\P_2 = 107.7 \ atm[/tex]
Therefore, the final pressure inside the container is 107.7 atm
In this experiment, you need to examine the idea of thermal energy transfer. Using a controlled experiment, what might a good question about the variables that affect thermal energy transfer be? Thermal energy transfer depends on many properties, but limit your question to only two.
Answer:
We shall consider two properties:
1. Temperature difference
2. Thermal conductivity of the material
Use a cylindrical rod of a given material (say steel) which is insulated around its circumference.
One end of the rod is dipped in a large reservoir of water at 100 deg.C and the other end is dipped in water (with known volume) at 40 deg. C. The cold water if stored in a cylinder which is insulated on all sides. A thermometer reads the temperature of the cold water as a function of time.
This experiment will show that
(a) heat flows from a region of high temperature to a region of lower temperature.
(b) The thermal energy of a body increases when heat is added to it, and its temperature will rise.
(c) The thermal conductivity of water determines how quickly its temperature will rise. If mercury replaces water in the cold cylinder, its temperature will rise at a different rate because its thermal conductivity is different.
Explanation:
Which of the following BEST summarizes the relationship between groups and culture and critical thinking?
Answer:
Groups and culture helps in influencing our values,ethics and beliefs. This influence should always be questioned through the process of thinking critically.
This best summarizes the relationship between groups and culture and critical thinking.
Which theory states that deviance results not only from what people do, but also from how others respond to those actions?
A.
strain theory
B.
labeling theory
C.
differential association theory
D.
control theory
E.
conflict theory
The theory states that deviance results not only from what people do but also from how others respond to those actions are labeling theory. Hence, the option B is correct.
What is labeling theory?This theory states that deviance and conformity result not so much from what people do but also from how others respond. It is called labeling theory. Eg: Skipping school, and underage drinking.
It also suggests that any deviance results in how society responds to certain behaviors. It defines the behavior of human beings influenced by other members of society.
It also notes that a person is made to act in a negative way by the manner in which society identifies him. If a person is identified as a criminal then he involves in the criminal activities.
Conflict theory refers to the theory linking deviance to social inequality. Anticipating the consequences of a person's behavior is control theory.
Hence, the correct option is B) labeling theory.
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During the process of mountain building, earthquakes sometimes occur along continental-continental convergent boundaries. Which statement best describes the motion of the plates along these boundaries that causes the earthquakes?
The plates push apart from each other with no subduction.
Subduction occurs with the less-dense plate sinking below the other plate.
Subduction occurs with the more-dense plate sinking below the other plate.
The plates smash together with no subduction.
Answer:
The correct answer is The plates smash together with no subduction. I just took this on Edge. Glad I could help!
The statement best describes the motion of the plates along these boundaries that causes the earthquakes is that The plates smash together with no subduction
For better understanding let's explain what the answer means
it is said that the meeting point of two tectonic plates will causea convergent plate boundary to be formed. one of the converging plates will move under the other as it is known as subductionFrom the above we can therefore say that the answer The statement best describes the motion of the plates along these boundaries that causes the earthquakes is that The plates smash together with no subduction, is correct
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I need some help!!!!!!!!!
Answer:
The Object will immediately begin moving toward the left
Explanation:
Because the force of thirteen is greater than ten and applied to the opposite side
