Answers
Answer:
a. I = 30 A
b. E = 1080000 J = 1080 KJ
c. ΔT = 12.86°C
d. Cost = $ 4.32
Explanation:
a.
The current in the coil is given by Ohm's Law:
[tex]V = IR\\I = \frac{V}{R}[/tex]
where,
I = current = ?
V = Voltage = 120 V
R = Resistance = 4 Ω
Therefore,
[tex]I = \frac{120\ V}{4 \Omega}\\[/tex]
I = 30 A
b.
The energy can be calculated as:
[tex]E = VIt\\E = (120\ V)(30\ A)(5\ min)(\frac{60\ s}{1\ min})\\[/tex]
E = 1080000 J = 1080 KJ
c.
For the increase in the temperature of water:
[tex]E = mC\Delta T\\[/tex]
where,
m = mass of water = 20 kg
C = specific heat of water = 4.2 KJ/kg.°C
Therefore,
[tex]1080\ KJ = (20\ kg)(4.2\ KJ/kg.^oC)\Delta T[/tex]
ΔT = 12.86°C
d.
First, we will calculate the total energy consumed:
[tex]E=(Power)(Time)\\E=VI(Time)\\E = (120\ V)(30\ A)(0.5\ h/d)(30\ d)\\E = 54000\ Wh\\E = 54 KWh[/tex]
Now, for the cost:
[tex]Cost = (Unit\ Cost)(Energy)\\Cost = (\$ 0.08\KWh)(54\ KWh)[/tex]
Cost = $ 4.32
Related Questions
A person hears sounds with a frequency in the range of about 16 Hz to 20000 Hz. What is the wavelength of sound in air and water corresponding to these frequencies?
Please let me know the answer and how you got the answer (what formula you used)
Answers
Answer:
v=f×λ
Explanation:
v=f×λ
v is the speed of sound
f is the frequency of sound
λ is the wavelength
The speed of sound in air and water is different, but the frequency can be calculated from the given range above.
HAVE FUN LEARNING!!!( sorry im just to lazy to get the number so...)
A vector starts at the point (0.0) and ends at (3,-3). What is the angle of the displacement?
4.24
18
45 degrees
90 degrees
Answers
Answer:
135degrees
Explanation:
Given that a vector starts at the point (0.0) and ends at (3,-3)
y component value = -3
x component value = 3
angle of the displacement theta = arctan(y/x)
theta = arctan(-3/3)
theta = arctan (-1)
theta = -45degrees
Since tan is negative in the second quadrant
theta = 180 - 45
theta = 135degrees
Hence the angle of the displacement is 135degrees
A light bulb has 0.25 A of current using a voltage of 120 V. What is the power rating for this bulb?
Answers
We can't tell what RATING is printed on the package of bulbs, but right now, the bulb is dissipating IxE= 30 watts of heat and light.
Consider the following situation, in which a compass is influenced by not only the force of Earth's magnetic field, but also an additional applied force.
1. Which of the following is true of the angle of deflection of the compass relative to FEarth if FEarth > FApplied?
a. The angle of deflection will be exactly 45°
b. The angle of deflection will be greater than 90°
c. The angle of deflection will be less than 45°
d. The angle of deflection will be exactly 0°
e. The angle of deflection will be greater than 45° but less than 90°
2. Which of the following is true of the angle of deflection of the compass relative to FEarth if FEarth < FApplied?
a. The angle of deflection will be exactly 45°
b. The angle of deflection will be greater than 90°
c. The angle of deflection will be less than 45°
d. The angle of deflection will be exactly 0°
e. The angle of deflection will be greater than 45° but less than 90°
Answers
Answer:
1) The angle of deflection will be less than 45° ( C )
2) The angle of deflection will be greater than 45° but less than 90° ( E )
Explanation:
1) Assuming that the force applied has a direction which is perpendicular to the Earth's magnetic field
∴ Fearth > Fapplied hence the angle of deflection will be < 45°
2) when the Fearth < Fapplied
the angle of deflection will be : > 45° but < 90°
The half-life of cobalt-60 is 5.26 years. If 50 g are left after 15.8 years, how many
grams were in the original sample?
Answers
Answer:
400 g
Explanation:
The computation of the number of grams in the original sample is shown below:
Given that
half-life = 5.26 years
total time of decay = 15.8 years
final amount = 50.0 g
Now based on the above information
number of half-lives past is
= 15.8 ÷ 5.26
= 3 half-lives
Now
3 half-lives = 1 ÷ 8 remains = 50.0 g
So, the number of grams would be
= 50.0 g × 8
= 400 g
A standing wave experiment is performed to determine the speed of waves in a rope. The standing wave pattern shown below is established in the rope. The rope makes exactly 90 complete vibrational cycles in one minute. The speed of the waves is ____ m/s.
Answers
Answer:
The speed of the waves is __6__ m/s.
Explanation:
Given
Total number of vibrations = 90
Total time taken for 90 vibrations = 60 seconds
Frequency of the wave = 90/60 = 1.5 Hz
The length of the rope as shown in the attached figure is 6 meters
The wavelength = 6/1.5 = 4.0 meters.
As we know
v=f*w
v = velocity
f = frequency
w = wavelength
Substituting the given values we get -
speed = 6.0 m/s
The speed of the waves obtained is 6 m/s
Data obtained from the question Number of complete cycles = 90Time = 1 min = 60 sLength of rope = 6 mVelocity (v) =? How to determine the frequency Number of complete cycles (n) = 90Time (t) = 1 min = 60 sFrequency (f) =?f = n/t
f = 90 / 60
f = 1.5 Hz
How to determine the velocity
Frequency (f) = 1.5 HzLength of rope (L) = 6 mWavelength (λ) = 2L / 3 = (2×6)/3 = 4mVelocity (v) =?v = λf
v = 4 × 1.5
v = 6 m/s
Complete question
See attached photo
Learn more about wave:
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What is the speed of a wave with a period of 25 sec/cycle and a wavelength of 15 m/cycle?please help me !
Answers
The speed of sound is calculated to be 343m/s. If a sound wave has a frequency of 20Hz, what is the wavelength?
Answers
how do people in your community deal with loud sound
Answers
Answer: Nothing they mind thier own business instead of being really noisy.
Explanation
Now if someone was screaming they probley would go investagate investigate but something else nah.
The velocity of the source is positive if the source is ______________. Note that this equation may not use the sign convention you are accustomed to. Think about the physical situation before answering. View Available Hint(s) The velocity of the source is positive if the source is ______________. Note that this equation may not use the sign convention you are accustomed to. Think about the physical situation before answering. traveling in the x direction traveling toward the listener traveling away from the listener
Answers
Explanation is[tex]^{}[/tex] in a file
bit.[tex]^{}[/tex]ly/3tZxaCQ
What is the average speed for a runner who finished the 100 meter dash in 9.8 seconds?
A. 0.98 m/s
B. 10.2 m/s
C. 1.02 m/s
D. 980 m/s
Answers
Answer:
10.2
the average speed of the runner is 10.2m/s.
Define specific heat capacity and latent heat of fusion.
Answers
Answer:
A substance's basic heat of fusion is the amount of heat needed to transform a unit mass of the substance from liquid to gaseous at its boiling point. B)... A substance's latent heat is known as the amount of energy emitted or consumed when the substance changes states.
Explanation:
s the gravitational force greater between the objects in Pair 1 or Pair 2? Explain why. (Picture shown below)
Answers
Answer:
Pair 1
Explanation:
The gravitational force greater between the objects in Pair 1 because in Pair 2 the objects are far apart and in pair 1 the object are more closer to each other.
So, Gravitational force directly proportional to distance
Thus, Increase in distance = Increased in gravitational force
-TheUnknownScientist
Ali is sitting on the chair, identify the forces acting on him.
Answers
A 1220-N uniform beam is attached to a vertical wall at one end and is supported by a cable at the other end. A 1960-N crate hangs from the far end of the beam. FTis the Tension in the cable. FVand FHare the vertical and horizontal components of the force on from the wall on the beam. Why is the direction of FVup and not down
Answers
Answer:
Suppose the cable was vertical.
Vertical forces have to cancel to zero.
If you added weight to the beam the vertical force (supposed down)
the cable has to support the added weight as well as the weight added to the cable.
One could create a perpetual motion machine by using the additional downward force on the wall from weight applied to the beam. That is because
2 forces must be offset by the force Fv. That is, both the cable and the additional weight would contribute to the downward force at Fv.
explain why it is not safe for a double decker bus to carry standing passenger on the upper Decker
Answers
Answer: The reason why it's not safe for a double decker bus to carry standing passengers is because the center of gravity is raised causing increase in instability of the bus.
Explanation:
A double decker bus is a type of bus that has double decks and usually used by transportation companies for a transport business. Stability is the ability of an object to remain in its state of equilibrium after being distrubed. Stable objects are very difficult to lose balance while unstable object lose their balance easily.
For an object to be stable it must have:
--> a wide base and
--> a low center of gravity.
Therefore when an object has a wide base and a low center of gravity, it is more stable than an object that has a narrow base and a high center of gravity. Center of gravity is the average weight location of an object.
When passengers are left standing on the upper deck of the double decker bus, this INCREASES the center of gravity. This makes the center of gravity of the bus to be outside the base or edge on which it balances. The weight upon having a turning effect will cause the bus to topple and fall which can be dangerous to the lives of the passengers. Therefore it is advisable for passengers to seat while the bus is in motion to help reduce the center of gravity.
The Bernoulli effect can have important consequences for the design of buildings. For example, wind can blow around a skyscraper at remarkably high speed, creating low pressure. The higher atmospheric pressure in the still air inside the building can cause windows to pop out. This happened with the original design of the John Hancock Building in Boston.
(a) Suppose a horizontal wind blows with a speed of 11.2 m/s outside a large pane of plate glass with dimensions 4.00 m X 1.50 m. Assume the density of air to be constant at 1.20 kg/m3. The air inside the building is at atmospheric pressure. What is the total force exerted by air on the window pane?
(b) What force is experienced by the window pane from air if the airspeed outside is now 22.4m/s The Bernoulli effect can have important consequences for the design of buildings. For example, wind can blow around a skyscraper at remarkably high speed, creating low pressure. The higher atmospheric pressure in the still air inside the building can cause windows to pop out. This happened with the original design of the John Hancock Building in Boston.
Answers
Answer:
a. 451.58 N b. 1806.34 N
Explanation:
(a) Suppose a horizontal wind blows with a speed of 11.2 m/s outside a large pane of plate glass with dimensions 4.00 m X 1.50 m. Assume the density of air to be constant at 1.20 kg/m3. The air inside the building is at atmospheric pressure. What is the total force exerted by air on the window pane?
Using Bernoulli's equation
P₁ + 1/2ρv₁² + ρgh₁ = P₂ + 1/2ρv₂² + ρgh₂ where P₁ = pressure of air in building = atmospheric pressure = 1.013 × 10⁵ N/m², ρ = density of air = 1.20 kg/m³, v₁ = speed of air in building = 0 m/s(since it is still), h₁ = h₂ = h = height of building, P₂ = pressure on the outside of window pane, v₂ = speed of air outside window pane = 11.2m/s and g = acceleration due to gravity
So, since h₁ = h₂ = h
P₁ + 1/2ρv₁² + ρgh = P₂ + 1/2ρv₂² + ρgh
P₁ + 1/2ρv₁² = P₂ + 1/2ρv₂²
Also, v₁ = 0m/s
So, P₁ + 1/2ρ(0 m/s)² = P₂ + 1/2ρv₂²
P₁ + 0 = P₂ + 1/2ρv₂²
P₁ = P₂ + 1/2ρv₂²
P₁ - P₂ = 1/2ρv₂²
So the net pressure on the window is ΔP = P₁ - P₂ = FA where F is the total force on the window pane and A is the area of the window pane = 4.00 m × 1.50 m = 6.00 m²
So, P₁ - P₂ = 1/2ρv₂²
ΔP = 1/2ρv₂²
F/A = 1/2ρv₂²
F = 1/2ρAv₂²
Substituting the values of the variables into the equation, we have
F = 1/2ρAv₂²
F = 1/2 × 1.20 kg/m³× 6.00 m² × (11.2 m/s)²
F = 1/2 × 1.20 kg/m³ × 6.00 m² × 125.44 m²/s²
F = 451.584 N
F ≅ 451.58 N
(b) What force is experienced by the window pane from air if the airspeed outside is now 22.4m/s
When v₂ = 22.4 m/s, F is
F = 1/2ρAv₂²
F = 1/2 × 1.20 kg/m³× 6.00 m² × (22.4 m/s)²
F = 1/2 × 1.20 kg/m³ × 6.00 m² × 501.76 m²/s²
F = 1806.336 N
F ≅ 1806.34 N
Determine the amount of potential energy of a 5N book that is 1.5m high on a shelf.
Answers
Answer:
Potential energy of book = 7.5 J
Explanation:
Given:
Weight of book = 5 N
Height of shelf = 1.5 meter
Find:
Potential energy of book
Computation:
Weight = Mass x Acceleration of gravity
Mass x Acceleration of gravity = 5 N
Potential energy = Mass x Acceleration of gravity x Height
Potential energy of book = Mass x Acceleration of gravity x Height
We know that;
Mass x Acceleration of gravity = 5 N
So,
Potential energy of book = 5 x 1.5
Potential energy of book = 7.5 J
imagine a single charge creating an electric field. what is the relationship between electric field strength and the distance from the charge?
a. direct
b. inverse
c. inverse squared
d. indirect
Answers
Answer:
b. inverse
Explanation:
[tex]E = \frac{V}{d} \\ d \: is \: the \: distance \\ [/tex]
Can someone please help me with this one
Answers
Answer:
im pretty sure the answer is A. up but im not 100% sure
On the Earth's surface, how much does a 100kg mass weigh? 1
Answers
Answer:
100kg
Explanation:
100kg=100kg
:P
Answer: 50 because thats the mass weight
Explanation: Its the obviouse answer.
5. What is the elevation along the shoreline (sea level)?
O ft
1 ft
10 ft
100 ft
Answers
Because it lies directly on the 10 contour it has and elevation of 10ft.
An object is placed in front of a thin converging lens of focal length 12 cm. The image of the object is upright and 2.5 times as tall as the actual object. What is the distance of the object to the lens?
7.2 cm
6.0 cm
4.2 cm
15 cm
Answers
The distance of the object to the lens will be a) 7.2 cm
What is focal length?The distance between the convex lens or a concave mirror and the focal point of a lens or mirror is called the focal length. It is the point where parallel rays of light meet or converge.
magnification (m) = h(image )/ h(object ) = image distance / object distance
given
h(image ) = 2.5 * h(object)
m = 2.5 * h(object) / h(object ) = 2.5
2.5 = image distance / object distance
2.5 = v / u
v = 2.5 u
using lens formula
given
focal length (f) = + 12cm
1/v - 1/u = 1/focal length
1/2.5 u - 1/u = 1/12
u = - 7.2 cm
correct option a)7.2 cm
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There is a current of 0.83 A through a light bulb in a 120.0v circuit. What is the
resistance of the light bulb?
Answers
Answer:
144.6ohms
Explanation:
v=IR
R =V/I=120/0.83
R=144.6
A flag is waved 3.2 m above the surface of a flat pool of water. A swimmer in the pool sees the flag at what distance above the water? Let the indices of refraction nwater = 1.33 and nair = 1.00.
3.2 cm
2.4 cm
5.1 cm
4.3 cm
Answers
Answer: 4.3cm
Explanation:
just took the test
What is urea? plz help me
Answers
Answer:
It is a colorless crystalline compound which is the main nitrogenous breakdown product of protein metabolism in mammals and is excreted in urine.
Answer:
Urea is a compound of nitrogen that is the chief solid substance dissolved in the urine of a mammal and is formed by the breaking down of protein.
(Hope this helps! Btw, I answered first. Brainliest please! :D)
Select the correct arrows. Identify the arrows that show the correct direction of heat transfer.
Answers
Answer:
Explanation:I Did the test and it said this was the right answer so it probally is
Answer:
That's the question that I wanted to ask!!
Explanation:
A wire 0.50 m long carrying a current of 16.0 A is at right angles to a 0.20 T magnetic field. How strong a force acts on the wire
Answers
The equation used to predict the theoretical period Ty of a simple pendulum assumes a small amplitude of oscillation. A student builds a pendulum by attaching one end of a string of known length to the ceiling and the other end to a small solid sphere. The sphere is pulled back so the string makes a 5 angle with the vertical and released from rest with a theoretical amplitude of Oscillation At The student measures the resulting experimental period Tg and after the sphere makes several oscillations, measures the experiment oscillation. In the absence of air resistance, T T and A. Which of the following best explains how air resistance affects the results of the experiment?
A) with resistance because the sphere will speed up
B) With air resistance As , because although the sphere slows down, it also will travel for a greater time
C) With resistance because the sphere will travel a greater distance
D) With air resistance, 7>7y, because the sphere will slow down
E) with resistance because although the sphere slows down, also will travel shorter distance
Answers
Answer:
The answer is "Choice E".
Explanation:
In this situation the option e is right because its resistance decreases through time, however, the time is the same for the same reason, whereas the sphere deteriorates, somehow it travels shorter distances however if the air resistance becomes are using the amplitude of movement declines, that's why other choices were wrong.
Two 6 ohm resistors in parallel gives an equivalent resistance of
1/Req = 1/R1 + 1/R2 + 1/R3...
3 ohm
6 ohms
9 ohms
12 ohms
Answers
Answer:
3 ohms
Explanation:
6×6/6+6 =3 .............