Correct question is;
A thermal tap used in a certain apparatus consists of a silica rod which fits tightly inside an aluminium tube whose internal diameter is 8mm at 0°C.When the temperature is raised ,the fits is no longer exact. Calculate what change in temperature is necessary to produce a channel whose cross-sectional is equal to that of the tube of 1mm. (linear expansivity of silica = 8 × 10^(-6) /K and linear expansivity of aluminium = 26 × 10^(-6) /K).
Answer:
ΔT = 268.67K
Explanation:
We are given;
d1 = 8mm
d2 = 1mm
At standard temperature and pressure conditions, the temperature is 273K.
Thus; Initial temperature; T1 = 273K,
Using the combined gas law, we have;
P1×V1/T1 = P2×V2/T2
The pressure is constant and so P1 = P2. They will cancel out in the combined gas law to give:
V1/T1 = V2/T2
Now, volume of the tube is given by the formula;V = Area × height = Ah
Thus;
V1 = (πd1²/4)h
V2 = (π(d2)²/4)h
Thus;
(πd1²/4)h/T1 = (π(d2)²/4)h/T2
π, h and 4 will cancel out to give;
d1²/T1 = (d2)²/T2
T2 = ((d2)² × T1)/d1²
T2 = (1² × T1)/8²
T2 = 273/64
T2 = 4.23K
Therefore, Change in temperature is; ΔT = T2 - T1
ΔT = 273 - 4.23
ΔT = 268.67K
Thus, the temperature decreased to 268.67K
B. Which of these uses the most power? Explain your answer.
1) 160 J of work in 8 seconds
2) 80 J of work is 4 seconds
3) 180 J of work in 9 seconds
Answer:
p=w/t
160/8=20
80/4=20
180/9=20
...so..all these uses equal power
6. What charge is in the nucleus?
a. negative charge
b. positive charge
C. no charge
d. positive and negative charges
Sam scored 98, 25, 105, 62 and 65 runs in 5 matches. What was the average score per match?
Answer:
71
Explanation:
Which lighting source has lower energy costs and a longer life but can be dangerous?
a. fluorescent
b. laser
c. incandescent
d. neon
Answer: I'm like 98% sure it's fluorescent cause it's got mercury
Explanation:
What is the acceleration of an object that has a mass of 10kg and is pushed with a force of 50n
Answer:
5m/s/s
Explanation:
force = mass x acceleration
50 = 10a
a=5m/s/s
What type of system is a black hole? Explain how you know.
Answer:
A black hole is a region of spacetime where gravity is so strong that nothing—no particles or even electromagnetic radiation such as light—can escape from it.[1] The theory of general relativity predicts that a sufficiently compact mass can deform spacetime to form a black hole.[2][3]
The boundary of the region from which no escape is possible is called the event horizon. Although the event horizon has an enormous effect on the fate and circumstances of an object crossing it, according to general relativity it has no locally detectable features.[4] In many ways, a black hole acts like an ideal black body, as it reflects no light.[5][6] Moreover, quantum field theory in curved spacetime predicts that event horizons emit Hawking radiation, with the same spectrum as a black body of a temperature inversely proportional to its mass. This temperature is on the order of billionths of a kelvin for black holes of stellar mass, making it essentially impossible to observe directly.
Objects whose gravitational fields are too strong for light to escape were first considered in the 18th century by John Michell and Pierre-Simon Laplace.[7] The first modern solution of general relativity that would characterize a black hole was found by Karl Schwarzschild in 1916, although its interpretation as a region of space from which nothing can escape was first published by David Finkelstein in 1958. Black holes were long considered a mathematical curiosity; it was not until the 1960s that theoretical work showed they were a generic prediction of general relativity. The discovery of neutron stars by Jocelyn Bell Burnell in 1967 sparked interest in gravitationally collapsed compact objects as a possible astrophysical reality.
Black holes of stellar mass are expected to form when very massive stars collapse at the end of their life cycle. After a black hole has formed, it can continue to grow by absorbing mass from its surroundings. By absorbing other stars and merging with other black holes, supermassive black holes of millions of solar masses (M☉) may form. There is consensus that supermassive black holes exist in the centers of most galaxies.
The presence of a black hole can be inferred through its interaction with other matter and with electromagnetic radiation such as visible light. Matter that falls onto a black hole can form an external accretion disk heated by friction, forming quasars, some of the brightest objects in the universe. Stars passing too close to a supermassive black hole can be shred into streamers that shine very brightly before being "swallowed."[8] If there are other stars orbiting a black hole, their orbits can be used to determine the black hole's mass and location. Such observations can be used to exclude possible alternatives such as neutron stars. In this way, astronomers have identified numerous stellar black hole candidates in binary systems, and established that the radio source known as Sagittarius A*, at the core of the Milky Way galaxy, contains a supermassive black hole of about 4.3 million solar masses.
On 11 February 2016, the LIGO Scientific Collaboration and the Virgo collaboration announced the first direct detection of gravitational waves, which also represented the first observation of a black hole merger.[9] As of December 2018, eleven gravitational wave events have been observed that originated from ten merging black holes (along with one binary neutron star merger).[10][11] On 10 April 2019, the first direct image of a black hole and its vicinity was published, following observations made by the Event Horizon Telescope in 2017 of the supermassive black hole in Messier 87's galactic centre.[12][13][14]
Blackness of space with black marked as center of donut of orange and red gases
The supermassive black hole at the core of supergiant elliptical galaxy Messier 87, with a mass about 7 billion times that of the Sun,[15] as depicted in the first false-colour image in radio waves released by the Event Horizon Telescope (10 April 2019).[16][12][17][18] Visible are the crescent-shaped emission ring and central shadow,[19] which are gravitationally magnified views of the black hole's photon ring and the photon capture zone of its event horizon. The crescent shape arises from the black hole's rotation and relativistic beaming; the shadow is about 2.6 times the diameter of the event horizon.[12]
Schwarzschild black hole
Simulation of gravitational lensing by a black hole, which distorts the image of a galaxy in the background
Gas cloud being ripped apart by black hole at the centre of the Milky Way (observations from 2006, 2010 and 2013 are shown in blue, green and red, respectively).[20]
What is the momentum of a 120 pound bicyclist that is traveling at 25 mph?
Select the correct answer.
Which diagram represents an object in equilibrium?
ОА.
applied
force = 20 N
force due to
friction = 15 N
OB.
applied
force = 20 N
force due to
friction = 20 N
OC.
applied
force = 15 N
force due to
friction = 25 N
OD.
applied
force = 30 N
force due to
friction = 20 N
ОЕ.
applied
force = 30 N
force due to
friction = 15 N
Reset
Next
My
Answer:
B
Explanation:
The force and friction cancel each other.
20N - 20N = 0N acting on the object.
Which of the following is a physical state of matter? *
A mass
B volume
C liquid
State the lows of reflection
Answer:
The law of reflection states that when a ray of light reflects off a surface, the angle of incidence is equal to the angle of reflection.
Explanation:
Answer: The law of reflection states that when a ray of light reflects off a surface, the angle of incidence is equal to the angle of reflection.
A tractor trailer truck traveling at a speed of 105 feet/second skids to a stop in 12 seconds. Determine the skidding distance of the truck.
Please help.
Answer:
1260ft
Explanation:
Given parameters:
Speed = 105ft/s
Time = 12s
Unknown:
Skidding distance of the truck = ?
Solution:
To solve this problem:
Distance = speed x time
Now insert the parameters and solve;
Distance = 105 x 12 = 1260ft
A current of 8 A flows through a conductor. The number of electrons passing through the conductor in each second will be
Answer:
8=3×1019 electrons per second.
Explanation:
Answer:
here
Explanation:8=3×1019 electrons per second.
Most metals have...
a. Atoms that are spread out, and low specific heats
b. Atoms that are close, and low specific heats
c. Atoms that are spread out, and high specific heats
d. Atoms that are close, and high specific heats
If the sun were to collapse into a black hole, what would the radius be?
Answer:
If the Sun, with its mass of 1 MSun, were to become a black hole the Schwarzschild radius would be about 3 kilometers; thus, the entire black hole would be about one-third the size of a neutron star of that same mass
Answer:
It would be 1/3rd size of a neutron star
Explanation:
the Schwarzschild radius would be about 3 kilometers; thus, the entire black hole would be about one-third the size of a neutron star of that same mass.
Transfer of charge by touching is called... induction or conduction?
Answer:
Transfer of charge by touching is called conduction.
Pleaaaase help meeee
Read the following case and discuss how you would respond to the situation.
PROBLEM:
You have been assigned the position of Environmental Engineer for one of several local
robotics manufacturers whose water discharges flow into a lake in a flourishing tourist area.
Although all the robotics companies in the area are marginally profitable, they compete for
the same customers. Included in your responsibilities is the monitoring of water and air
discharges
at your plant and the periodic preparation of reports to be submitted to the Department of
Natural Resources. You have just prepared a report that indicates that the
level of pollution in the plant's water discharges slightly exceeds the legal limitations. Your
boss, the Plant Manager, says you should regard the excess as a mere
"technicality," and he asks you to "adjust" the data so that the plant appears to be in
compliance. He says that the slight excess is not going to endanger human or fish
life any more than if the plant were in compliance. On the other hand, he says, solving the
problem would require a very heavy investment in new equipment. He
explains, "We can't afford new equipment. It might even cost a few jobs. It will set us
behind our competitors. Besides the bad publicity we'd get, it might scare off
some of the tourist industry, making it worse for everybody."
1) How do you think you should respond to your boss's request? Explain :
2) Define the problem :
3) what are the possible results of decision?
4) is there any information about the situation that is not obvious or available in the paragraph?
5) what are the ethical issues to consider in this situation
6) How did you decide to handle the situation what did you decide to do?
Answer:
3
Explanation:
Please helpp !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
A boxer pushes on a 25 kg heavy bag which is attached to the ceiling until it makes an angle of 36 degrees to the vertical. How much force must the boxer exert on the bag?
Answer:
198.20 N
Explanation:
Given that,
Mass of a heavy bag, m = 25 kg
The bag is attached to the ceiling until it makes an angle of 36 degrees to the vertical.
We need to find the force must the boxer exert on the bag. The force acting on the bag is given by :
[tex]F=mg\cos\theta\\\\=25\times 9.8\times \cos(36)\\\\=198.20\ N[/tex]
So, the required force is 198.20 N.
please help, brainest if correct
Answer: B
Its b increased risk of disease
Which of the following is a layer of the solid Earth? A. convecting mantle B. Ring of Fire C. biosphere D. atmosphere
Answer:
It's a cause that's the last layer
Answer:
I believe the answer is A
Explanation:
It is not the ring of fire because the ring of fire is the result of tectonic plates moving. It is not the biosphere because biosphere is the regions of the surface. The convecting mantle is the solid layer of the Earth because the mantle is mostly solid. The atmosphere is a solid plastic layer of the Earth. I hope this helps.
Please Help Me!!!........
Answer:
B
Polar covalent bonds and van dar Waals forces are weak attractive forces between discrete molecules of a simple molecular structure.
Ionic bonds are strong electrostatic forces of attraction between oppositely charged ions.
Hydrogen bonds are very strong bonds between hydrogen and a highly electronegative atom e.g Oxygen, fluorine, nitrogen
The speed you read on a speedometer is ____.
Answer:
[tex]\leq 40[/tex]
Explanation:
So if you’re going 40mph, your speedometer may read up to 50.25mph - but it can never read less than 40mph. In order to stay within the law, carmakers calibrate their speedometers to slightly overreport their vehicles' speeds.
a skydiver has a mass of 50.5 kg what is the force of weight on the sky diver?
F= _N
Answer:
The answer is 494.9 N
Explanation:
I got this same question, and it worked for me! Hope this helps <3
A 120 Ω resistor, a 60 Ω resistor, and a 40 Ω resistor are connected in parallel and placed across a potential difference of 12.0 V. What is the equivalent resistance of the parallel circuit?
Answer:
The equivalent resistance of the parallel circuit would be 20 Ω
Explanation:
To calculate the resistance of resistors connected in parallel, the formula to be used is
1/R = 1/R₁ + R₂ + R₃ + R₄...
1/R = 1/120 + 1/60 + 1/40
1/R = (1 + 2 + 3)/120
1/R = 6/120
1/R = 1/20 Ω
This can be rewritten or cross-multiplied to be
R × 1 = 20 × 1
R = 20 Ω
The equivalent resistance (R) would then be 20 Ω
What is the net force EF?
Answer:
Physics Net Force
Explanation:
Physics Net Force
The net force is the combined force of all individual forces acting on an object. Newton's First Law can be seen to be the special case in the Second Law when F, the net force, is zero. When that happens, the acceleration a must also be zero.
Hope this helped you!!
A train leaves the station heading south on the tracks. It takes the train 5 seconds to reach 50 miles per hour. It completes the entire 100-mile trip in two hours. Calculate the train's average speed and velocity over the two-hour trip. Show your work. Identify if each of the measurements are a scalar or vector quantity
help!! what are the blanks???
The earth receives energy from the sun in one day than all the energy consumed by humans in one year.
Amount of energy received from the sun
The sun provides around 174 petawatts of energy to Earth, of which 89 petawatts is absorbed by the planet.
The Global energy consumption is roughly 15 terawatts annually.
Thus, we can conclude that, the earth receives energy from the sun in one day than all the energy consumed by humans in one year.
Learn more about energy of sun here: https://brainly.com/question/2193109
#SPJ1
According to the law of conservation of energy, mechanical energy can be changed to heat energy.
Answer:
The answer to this question is given below in this explanation section.
Explanation:
" law of conservation of energy"
The law of conservation of energy states that energy can neither be created nor destroyed only converted from one form of energy into another.This mean that a system always has a same account of a energy,unless it is added from the outside.This is particularly confusing in the case of non conversation forces,where energy is converted from ,mechanical energy into thermal energy.but the overall energy does remain the same.The only way to use energy is to transform energy from one form to another.
The amount of energy in any system than it is determined by the following equation.
Ut=Ui +W+Q
Ut is the total internal energy of a system.Ui is the initial internal energy of a system.W is the work done by or on the system.Q is the heat added to or removed by the system.It is also possible to determined the change in internal energy of the system using the equation.
ΔU=W+Q
The mechanical energy of a system increases provided their is no loss of energy due to friction.The energy would transform to kinetic energy when the speed is increasing.Te mechanical energy of a system remain constant provided their is no loss of energy due to friction.
The law of conversation of energy which say that in a closed system total energy is conserved that is it constant.
KE1 + PE1=KE2+PE2
A force has both______ and _______. Question 3 options: Magnitude & Direction Direction & Motion Speed & Impact Speed and Direction
Answer:
A force has both Direction and Motion.
Explanation:
For example, when finding acceleration you take the time and divided it by distance. If the thing you are measuring is going in the positive direction, the acceleration will be positive and if it is going in the negative direction the acceleration will be negative.
Magnitude and Direction
Explanation:
Force is a Vector Quantity
As learned in an earlier unit, a vector quantity is a quantity that has both magnitude and direction. To fully describe the force acting upon an object, you must describe both the magnitude (size or numerical value) and the direction.
If you and your friend are playing tug of war and both are you are pulling with the same amount of force. What will happen?
Answer:
Nothin will move, it will stay the same since no force is greater than the other. it's "the same amount of force" which also means an equal amount of force
Explanation:
The forces are only equal if there is no acceleration (which in the game of tug of war, accelerating yourself and your opponent is the idea). If the force on the rope and the ground are both equal either nothing moves or some other force is being applied in the system.
Hope this helped!
