Answer:
Ek = 720J
Explanation:
Ek = 0.5mv^2
Ek = 0.5(90)(4)^2
Ek = 720J
Rob is studying for an exam. He listed some properties of magnets in a Maglev train.
A 2-column table with 2 rows. The first column labeled Magnet has entries Guidance, Guideway. The second column labeled Properties has entries the current in an electromagnet changes rapidly, which pushes the train forward, a pole faces the like pole of the support magnet and repels the support magnet, which increases friction.
Which best explains Rob’s error?
The current in the electromagnet of the guidance magnet does not change.
The types of magnets are listed incorrectly in the table and should be switched.
The unlike poles of the guideway and support magnets face each other.
The repelling of the support magnet decreases friction.
In the table's Properties column, notably in the entry for the Guidance magnet, Rob made a mistake.
Which best demonstrates Rob's inaccuracy that causes the friction?It is untrue to say that a quickly changing electromagnet's current propels a train forward. To create a levitation force that lifts the train off the tracks and enables it to float, the guidance magnets in a Maglev train really work by repelling the guiding magnets on the vehicle from the guideway.
In order to maintain the train's levitation and stability, the polarity of its steering magnets must change quickly rather than the current.
Superconducting magnets, which don't suffer any major energy losses when repelling another magnet, are frequently used in Maglev trains. Instead, a repelling force produced by the magnets lifts the train off the rails and enables it to float.
The mistake is that the guidance magnets should push the train ahead and increase friction, not by repelling the magnets on the train from the guideway and creating a levitation force.
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An airplane starts from rest and accelerates at a constant 3.00 m/s2 for 30.0 s before leaving the ground. a. How far did it move
The airplane that starts from rest and accelerates at 1 constant 3 m/s2 for 30 s before leaving the ground moved by the distance of 1350m.
Acceleration is given as 3.00 m/s2
Time is 30 sec.
The formula we can use in this case is:
s = ut + 0.5 at^2
v = at + u
where,
s is distance travelled
u is initial velocity = 0 since at rest
t is time travelled
a is acceleration
v is the final velocity when it took off
a. s = 0 + 0.5 * 3 * 30^2
s = 1350 m
The distance moved by the airplane is 1350 m.
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7 Someone is trying to balance a (110cm) plank with certain forces. a) Calculate the moment of the 60N force (about O), then name its type. b) Calculate the moment of the 30N force (about O), then name its type c) Will the plank balance? If not, which way will it tip? d) What extra force would be needed at (B) to balance the plank?
Answer:
(a) 30 Nm. Clockwise moment
(b) 15 Nm Anti clockwise
(c) Not balance, it tip to the clockwise direction
(d) 150 N
Explanation:
Assumimg the diagram attached is required to complete the question,
(a) Moment of 60 N force (about O) is
Moment = Force(F)× perpendicular distance (d)
M₁ = F₁d₁................ Equation 1
From the diagram, F₁ = 60 N, d₁ = 50 cm = 0.5 m
M₁ = 60×0.5
M₁ = 30 Nm. Clockwise moment.
(b) The moment of the 30 N force (about O) is given as
M₂ = F₂d₂
From the diagram, F₂ = 30 N, d₂ = 50 cm = 0.5 m
M₂ = 30×0.5
M₂ = 15 Nm Anti clockwise
(c) The plank will not balance because the sum of clockwise moment is not equal to the sum of anti clock wise moment. It tip to the clockwise direction.
(d) From the diagram,
Applying the principle of moment,
Sum of clockwise moment = sum of anti clockwise moment.
30(0.5)+X(0.1) = 60(0.5)
15+0.1X = 30
0.1X = 30-15
0.1X = 15
X = 15/0.1
X = 150 N.
What kind of force do you exert on an object when you pull it towards you?
A. applied force
B. attractive force
C. drag force
D. normal force
By definition we have to:
Applied force: It is the external force that acts directly on a body.
Therefore, we can say that if you have an object and push it towards yourself, you are exerting an external force on the object.
This external force was not acting on the object previously, therefore, it is a force that you are applying at that moment.
Answer:
you exert an Applied Force on an object when you pull it towards you
A. Applied Force
Use the vocabulary in the Word Bank to complete the following explanation.
Answer:
1.Magnetic field
2.Potential energy
3.Magnetic force
4.kinetic energy
According to legend, the evidence that stimulated Newton to propose the law of universal gravitation emerged from a study of ____. a. the motion of the moon and other celestial or heavenly bodies b. the fall of an apple to the Earth c. the gravitational interaction of smaller objects upon the Earth d. ...nonsense! There was no evidence; it was just proposed as a theory.
According to legend, the evidence that stimulated Newton to propose the law of universal gravitation emerged from a study of the motion of the moon and other celestial or heavenly bodies.
Newton made a comparison between the moon's acceleration and that of earthly objects. Newton was able to make a significant discovery regarding the relationship between gravity and distance by assuming that gravitational forces were in charge of each.
He came to the conclusion that the force of gravitational attraction between the Earth and other objects is inversely proportional to the separation between the centres of the two objects as a result of this comparison. But there are other factors than distance that might impact how strong a gravitational force is.
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Roughly how high could a 300 K copper ball lift itself if it could transform all its thermal energy into work?
Answer:
1181.63 m
Explanation:
Assume : specific heat for copper = 386 J/kg.k
Determine the height a 300k cu ball can lift itself after transforming all its thermal energy to work
Total thermal energy of ball = 386J/kg.k * 300 k
= 115800 J
when we convert to potential energy ( work ) applying the law of conservation of energy
11580 J = mgh
11580 = 1 * 9.8 * h ( note m = 1 because the cu is just 1 unit )
∴ h ( height attained ) = 11580 / 9.8 = 1181.63 m
There is no limit to the mass with which a star can be born.
True
false
The statement is False, there is no limit to the mass with which a star can be born.
A star is a celestial body comprised of a mass of gas, primarily hydrogen and helium, that gives off heat and light through nuclear fusion reactions in its core. Stars are the most widely recognized astronomical objects and serve as a fundamental reference point in astronomy. Stars come in a variety of sizes and colors and are classified based on their temperature, size, and luminosity.
There are many different types of stars, including main-sequence stars, red giants, white dwarfs, and neutron stars. Stars are formed when large clouds of gas and dust collapse under the force of gravity, causing the material to heat up and form a protostar. Over time, the protostar becomes hot enough to trigger nuclear fusion reactions, and it is at this point that the star becomes visible to observers on Earth. Stars eventually die out, either exploding as supernovae or fading away as white dwarfs. Starlight is the source of illumination for our night sky, and the beauty of stars has captivated humans since the dawn of time.
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The speed of sound is determined by the temperature and density of the medium through which it travels. Based on the speed data above, which choice below lists the media in order from most to least dense?
A. Wood, water, air
B. Air, water, wood
C. Air, wood, water
D. Wood, air, water
Answer:
A?
Explanation: put them in order
Sorry if its wrong...
Answer:
It's A
Explanation:
It wants it in order from most dense to least. Wood is most dense so it's first, then water, and then air is last.
Does changing amplitude, wavelength or frequency play a role in how bluetooth acts?
Answer:
Yes
Explanation:
Yes, bluetooth devices work in a frequency range between 2.4 - 2.485GHz. Outside this frequency the devices will not communicate with each other correctly. This frequency equals a wavelength of around 1cm. Therefore, any change in the amplitude or wavelength would need to be in relation to each other in order to maintain the frequency in the required range for the bluetooth device to work accordingly. If one increases while the other remains the same it can easily change the frequency to outside the range.
What is the relationship between changes in air pressure in wind speeds, answers, when a high and low pressure, air mass or close together. It moves slowly from high to low pressure, when I have high and low pressure MS are far apart and is quickly from low to high pressure, when a high and a low pressure area, so far apart, and move slowly from high to low pressure, when a high in a low
Answer:
Explanation:
Gases move from high-pressure areas to low-pressure areas. And the bigger the difference between the pressures, the faster the air will move from the high to the low pressure. That rush of air is the wind we experience.
Answer:
points are needed
Explanation:
You have seen how large Jupiter would be if the Sun were a 1 meter sphere. Using the same scale, how large would the other planets be
After seeing how big Jupiter is if the Sun were just a sphere measuring one meter in diameter. If somehow the solar is 1,391,000,000 meters diameter, so its diameter, if it had been a sphere, would be 7.2 × 10⁻¹⁰.
Describe planet.Celestial bodies that fit the following descriptions are considered planets: It has cleansed the space around and within its orbit because (a) it is orbiting the Sun; (b) it possesses sufficient mass for its soul to outweigh rigid body forces; and (c) it has orbited the Sun.
How far is it?An object's distance is equal to its overall directionless velocity. Depending of where it started or concluded, distance is really the amount of territory that an object has covered.
Mercury: 0.0035 meters
Venus: 0.0087 meters
Earth: 0.0092 meters
Mars: 0.0049 meters
Jupiter: 0.1028 meters
Saturn: 0.086 meters
Uranus: 0.0367 meters
Neptune: 0.0356 meters
Therefore, you have seen how large Jupiter would be if the Sun were a 1 meter sphere, the other planets distance are described above .
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After seeing how big Jupiter is if the Sun were just a sphere measuring one meter in diameter. If somehow the solar is 1,391,000,000 meters diameter, so its diameter, if it had been a sphere, would be 7.2 × 10⁻¹⁰.
Describe planet:Planets are celestial bodies that match the following criteria: Because it is circling the Sun, has enough mass for it's own soul to override rigid body forces, and has orbited the Sun, it has cleaned the space in and around its orbit.
How far is it?The distance between two objects is equal to their combined directionless velocity. Distance is basically the amount of ground that only an object has traveled, depending on where it began and ended.
Mercury: 0.0035 meters
Venus: 0.0087 meters
Earth: 0.0092 meters
Mars: 0.0049 meters
Jupiter: 0.1028 meters
Saturn: 0.086 meters
Uranus: 0.0367 meters
Neptune: 0.0356 meters
Therefore, you have seen how large Jupiter would be if the Sun were a 1 meter sphere, the other planets distance are described above .
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what is the relationship between star temperature and luminosity in the main sequence
The relationship between star temperature and luminosity in the main sequence is known as the main sequence mass-luminosity relationship.
What is luminosity?
Luminosity is the amount of light and other forms of electromagnetic radiation emitted by a star, galaxy, or other celestial object. It is typically measured in units of watts per square meter (W/m2). Luminosity is related to the total energy output of a star or other celestial body and is an important factor in determining its temperature, composition, and other physical properties.
This relationship states that the hotter the star, the more luminous it is. This is because hotter stars are more massive and more luminous than cooler stars. As the star's temperature increases, so does its luminosity.
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where does sound travel faster(the desert or the forest)?
Answer:
forest
Explanation:
cause of the echo
Answer:
forest
Explanation:
very spacious enough to make echo
Of the following objects, on which one would time on its surface run most slowly?
a. An object with the same mass as the Sun but twice as large in radius
b. The Sun
c. An object with the same mass as the Sun but only half as large in radius
The time on the surface of an object would run most slowly on an object with the same mass as the Sun but twice as large in radius.
What is mass?
Mass is a measure of the amount of matter in an object and is typically expressed in kilograms (kg). It is an intrinsic property of matter and is different from weight, which is a measure of the force of gravity acting on an object. Mass is an important factor in determining the physical properties of an object, such as density, momentum, and inertia. Mass is also used to calculate the gravitational force between two objects, as well as the energy required to move it.
This is because the surface gravity of an object is inversely proportional to the square of its radius. Therefore, the object with the same mass as the Sun but twice as large in radius would have a much lower surface gravity, and time would run more slowly on its surface.
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Give an example of a fossil fuel in each of the three phases ( solid,liquid, and gas
Answer:
coal , oil and natural gas
You may think of a sheet of aluminum foil as a 2D object, but it is really a 3D object because it has a non-zero thickness. Consider a sheet of aluminum foil that is 17.4 inches by 14.8 inches and has a mass of 10.8 grams. Of the density of aluminum is 2.7 g/cm3, what is the thickness of the foil in mm
Answer:
Below
Explanation:
17.4 inches = 441.96 mm 14.8 inches = 375.92 mm
volume = 441.96 X 375.92 X T
= 166141.6 T mm^3 <===where T = thickness in mm
Volume X density = mass
166141.6 T mm^3 * 2.7 gm/cm^3 * cm^3 / 1000mm^3 = 10.8 gm
solve for T = .024 mm
Can nuclei of the same element have different values of Z? Of N? Of A?
Check all that apply.
O 1 Nuclei of the same element must have the same values of Z, N, and A.
O 2 Nuclei of the same element can have different values of Z.3
O 3 Nuclei of the same element can have different values of A.
O 4 Nuclei of the same element can have different values of N.
Nuclei of the same element can have different values of Z, N, and A, as these values are all related to the number of protons, neutrons, and nucleons in the nucleus, respectively. Therefore, option 2, 3, and 4 are correct.
Nuclei of the same element can have different values of Z, N, and A due to the number of protons, neutrons, and nucleons they contain, respectively. This is because the number of these particles in the nucleus can vary, although they all will still be the same element. Therefore, option 2, 3, and 4 are correct and option 1 is incorrect.
Nuclei of the same element can have different values of Z, N, and A, as these values are all related to the number of protons, neutrons, and nucleons in the nucleus, respectively. Therefore, option 2, 3, and 4 are correct.
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When a car has a dead battery, it can often be started by connecting the battery from another car across its terminals. The positive terminals are connected together as are the negative terminals. The connection is illustrated in Fig. P1.15. Assume the current i in Fig. P1.15 is measured and found to be 30A. a) Which car has the dead battery? b) If this connection is maintained for 1 min, how much energy is transferred to the dead battery?
Explanation:
convert 1= 30 amp
which Car has the dead
battery ?
CarA
Car B
Ams => The Current i flows into the of the Battery of Qax A.
Posithe terminal
So. By using Passinge sign Convention.
Power P₁ = Vi = 12X 30
PA = 360 Watt (the)
=>Power is Positive So Car Ahabsorbing So now we can say car A has dead battery.
Power,
Connection is maintained for t = 1 min. Energy toonsffered to the dead battery
=> we know w(t) = Work = Emergy t S. Pdt fo W (1 = imin) = 360 dt
t = 60 sec = 1 min.
36. (t), 60
360 X60
|w[t=1mm) = 21.60 *Jure.
Please give an explanation on how to do this
The time that is taken by the cart is given as 34.7 s.
What is the time taken?
Let us have it at the back of our minds that what we are dealing with here is the velocity and that the velocity of the object can be said to be a vector quantity. If it is a vector quantity, we would need to look at the magnitude and the direction of the quantity.
We can now see that the velocity of the object can be defined as the change in the velocity of the object with time. We can now write;
V = Δx/t
V = velocity
Δx = change in the displacement
t = time
Then;
-0.418 = 5.40 - 19.9/t
t = -14.5/-0.418
t = 34.7 s
In the movement of the cart from one point on the plane to the other, the time that has been taken by the cart is about 34.7 s.
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Abbey and Mia are in the basement playing pool. On Abbey's recent shot, the cue ball was moving east at 82 cm/s when it struck the slower 5-ball moving in the same direction at 24 cm/s. The 5-ball immediately speeds up to 52 cm/s. Determine the post-collision speed of the cue ball.
Answer:
v₁ = 54 cm/s
Explanation:
This question can be solved using the law of conservation of momentum:
[tex]m_1u_1+m_2u_2=m_1v_1+m_2v_2[/tex]
where,
m₁ = m₂ = m = mass of both balls
u₁ = pre-collision speed of cue ball = 82 cm/s
u₂ = pre-collision speed of 5-ball = 24 cm/s
v₁ = post-collision speed of cue ball = ?
v₂ = post-collision speed of 5-ball = 52 cm/s
Therefore,
[tex]m(82\ cm/s)+m(24\ cm/s)=m(v_1)+m(52\ cm/s)\\v_1 = 82\ cm/s + 24\ cm/s - 52\ cm/s\\[/tex]
v₁ = 54 cm/s
An automobile travels on a straight road at 30 km/h How long will it take to travel 40 km
Answer:
the time taken for the automobile to travel the given distance is 80 mins.
Explanation:
Given;
speed of the automobile, v = 30 km/h
distance traveled by the automobile, x = 40 km
The time taken for the automobile to cover the given distance is calculated as;
time = distance / speed
time = 40 / 30
time = 1.3333 hours = 1.3333 hr x 60mins/hr = 80 mins
Therefore, the time taken for the automobile to travel the given distance is 80 mins.
calculate their densties in Si unit.
200mg,0.0004m
Question: calculate their densties in Si unit.
200mg,0.0004m³
Answer:
0.5 kg/m³
Explanation:
Applying,
D = m/V........................ Equation 1
Where D = density, m = mass, V = volume.
From the question,
Given: m = 200 mg = (200/1000000) kg = 2.0×10⁻⁴ kg, V = 0.0004 m³ = 4.0×10⁻⁴ m³
Substitute these values into equation 1
D = (2.0×10⁻⁴ kg)/(4.0×10⁻⁴)
D = 2/4
D = 0.5 kg/m³
Hence the density in S.I unit is 0.5 kg/m³
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Explanation:
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In general, how can you calculate the distance of object B from the fulcrum so that it balances object A
The formulas F(A)×R(A) = F(B)×R(B) should be used to determine the distance of item B from the fulcrum such that it balances object A. where F is the object's force and R is the object's distance from the fulcrum.
What does "force" actually mean?The push or pull that causes a massed body to change its speed is the definition of force. An agent with the ability to change a body's rest or moving condition is known as an external force. It has a magnitude as well as direction.
How come forces occur?Forces are created by the interactions between two (or more) objects. There is a similar but opposing force acting on each individual on the other. External forces are what cause the item to move.
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What is a disadvantage of using fuses? A.When a fuse burns out, it cannot be used again b.
A fuse shuts off when the current gets too high c. A fuse contains a thin strip of metal that can melt d. A fuse prevents circuits from overheating
A 2,000-kg elevator is being accelerated upward at a rate of 3.0 m/s2. What is the tension in the cable
According to the above statement, 15800 N of tension is required to draw a cable at 3.0 m/s² of acceleration.
What are potential and tension?A force known as tension is connected here to tugging of an item like the a rope, cord, or chain. It resembles elastic potential energy a lot. When a thing is pulled out and brought under tension, as soon as that force is removed, it will naturally recover to its relaxed length.
F = ma
= 2000 kg × 3.0 m/s²
= 6000 N.
The body's weight and the load are added to create the tension force.
Thus T = w + ma
T = 9800 N + 6000 N
= 15800 N.
As a result, 15800 N of tension is required to draw a wire at 3.0 m/s² of acceleration.
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The complete question is-
A 2000 kg elevator is accelerated upward at a rate of 3.0 m/s2. What is the tension in the cable pulling the elevator upward when it experiences this acceleration?
A ball is tossed straight up from the surface of a small spherical asteroid with no atmosphere. The ball goes to a height equal to the asteroid's radius and then falls straight down toward the surface of the asteroid. What forces if any act on the ball while it is on the way up?
a. only a decreasing gravitational forces acts downward
b. only an increasing gravitational force that acts downwards.
c. only a constant gravitational force that acts downwards
d. Both a constant gravitational force that acts downwards and a decreasing force that acts upwards.
e. No forces act on the ball
'Only a decreasing gravitational force that acts downward' act on the ball while it is on the way up.
What is gravitational force?
Gravitational force is the force of attraction between two objects that have mass. It is the force of gravity that causes objects to be pulled towards each other. The strength of the force depends on the mass of the objects and the distance between them.
Since the ball is moving away from the Earth, the gravitational force between the two objects is decreasing. The ball does not experience any upward force and thus the only force acting on it is the decreasing gravitational force that acts downward.
Hence, Option A is correct.
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Convert 9.83 m/s with a radius of 0.85 m to rotations per minute (rpm)
Answer: Conversion of 9.83 m/s with a radius of 0.85 m into rotations per minute (rpm) is [tex]99.25 m^{-1}[/tex].
Explanation:
Given: Speed = 9.83 m/s
Convert m/s into m/minute as follows.
[tex]1 min = 60 sec\\9.83 m/s = 9.83 m/s \times \frac{60 s}{1 min}\\= 529.8 m/min[/tex]
Radius = 0.85 m
Now, rotations take place in circular motion. So, the circumference of a circle is [tex]2 \pi r[/tex].
Therefore, circumference is calculated as follows.
[tex]Circumference = 2 \times pi \times r\\= 2 \times 3.14 \times 0.85 m\\= 5.338 m[/tex]
Formula used to calculate rotations per minute (rpm) are as follows.
[tex]rpm = \frac{speed (in meter per minute)}{circumference}\\= \frac{529.8 m/min}{5.338 m}\\= 99.25 m^{-1}[/tex]
Thus, we can conclude that conversion of 9.83 m/s with a radius of 0.85 m into rotations per minute (rpm) is [tex]99.25 m^{-1}[/tex].
If a container is stressed beyond its limits of recovery and opens up, then it is in this event of the General Hazardous Materials Behavior Model.
A container is said to have breached when it has been overstressed beyond its point of recovery.
The GEBMO model enables a systematic evaluation of the outcomes that are most likely to occur when a hazardous material container is strained. Hazardous material containers typically have the capacity to hold that material under typical shipping, storage, and use circumstances. Thus, API gravity is a measure of the density of a petroleum liquid in relation to water (also known as specific gravity). It is used to compare petroleum liquid densities. For instance, if one petroleum liquid has a higher API gravity than another because it is less dense.Specific gravity (Sp.Gr. or SG) is the weight or density of a liquid or solid relative to water. Floaters and sinkers have specific gravities below that of water and are very immiscible with itTo know more about Hazard here
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