Answer:
A stone is more dense than water and the air in draft of the boat is less dense than water.
derive an expression for resistivity of conductor of length l and area of cross section A
Answer
Resistivity R = K * L / A where resistivity is constant for material, L the length of the material and A the area of the material
K = R * A / L where R is the resistance of the material
What do is mean by environment friendly behaviour?
4 A student says that he has made a magnetic field with some iron filings. What would
you say to him?
Answer:
Yes but no
Explanation:
Here the kid cant say that he has created s magnetic field as iron fillings do not have magnetic properties
when an apple falls towards the earth the earth moves up to meet the apple. Is it true? If yes, why is the earth motion not noticeable ?
Answer:
Yes, this is true.
-- While the apple is falling, the same gravitational force acts on both the apple and the Earth.
-- The mass of the apple is somewhere in the neighborhood of 1/4 kg.
-- The mass of the Earth is about 5.972 x 10²⁴ kg.
-- Since the Earth has roughly 2.389 x 10²⁶ times as much mass as the apple has, the apple has roughly 2.389 x 10²⁶ greater acceleration than the Earth has, and moves roughly 2.389 x 10²⁶ times as far down as the Earth moves up, before they smack together.
-- That's why you don't notice the Earth's motion.
-- Also, you're standing on the Earth, moving up with it, toward the apple. Maybe it would be different if you were sitting on the apple, riding it down to the ground, and you were able to notice the motion of the ground coming up to meet you at a speed that's 0.00000000000000000000000000419 of YOUR speed.
Answer From Gauth Math
A man stands still on a moving walkway that is going at a speed of 0.2 m/s to
the west. What is the velocity of the man according to a stationary observer?
A. 0.2 m/s north
B. 0.2 m/s west
C. 0.2 m/s South
D. 0.2 m/s east
When,a man stands still on a moving walkway that is going at a speed of 0.2 m/s to the west,then the velocity of the man according to a stationary observer would be 0.2 m/s west,Therefore, the correct answer would be option B.
What is Velocity?The total displacement covered by any object per unit of time is known as velocity. The velocity of an object is depend on the magnitude as well as the direction of the object.
the mathematical expression for velocity is given by
velocity = total displacement /time
The speed and velocity of the object are very different from each other because speed does not depend upon the direction of the moving object but velocity depends on the magnitude of speed as well as the direction of the moving object.
As per given in the problem a man stands still on a moving walkway that is going at a speed of 0.2 m/s to the west therefore from the perspective of a stationary observer the velocity of man would be 0.2 m/s towards West.
Hence the correct options for the problem would be option B.
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20. A semiconductor is a
A) crystalline solid that conducts current under any condition
B) metallic solid that conducts current under any condition
C) metallic solid that conducts current under certain conditions
D) crystalline solid that conducts current under certain conditions
Answer:
D) crystalline solid that conducts current under certain conditions
Explanation:
A semiconductor is any crystalline solid material whose electrical conductivity is intermediary between that of insulators and conductors. That is, a semiconductor does not conduct like a conductor but does more than an insulator.
Based on this, a semiconductor is said to only conduct electricity under certain conditions as opposed to conductors that do so under any condition. Example of semiconductors are silicon, carbon, antimony, arsenic etc.
The moon Phobos orbits Mars
(mass = 6.42 x 1023 kg) at
a distance
of 9.38 x 106 m. What is its period of
orbit?
[?]s
Answer:
Explanation:
We are basically needing to solve for the time in the equation d = rt, where d is the distance around Mars (aka the circumference), r is the velocity, and t is time. We need to find the circumference and the velocity. We will begin with the velocity.
Because the gravitational attraction between Phobos and Mars provides the centripetal acceleration necessary to keep Phobos in its (sort of) circular path, the equation we use for this is:
[tex]F_g=F_c[/tex] which says that Force supplied by gravity is equal to the centripetal force. Expanding that:
[tex]\frac{Gm_{Phobos}m_{Mars}}{r^2}=\frac{m_{Phobos}v^2}{r}[/tex]
When we move that around mathematically to solve for the velocity value, what we end up with is:
[tex]v=\sqrt{\frac{Gm_{Mars}}{r}[/tex] and filling in:
[tex]v=\sqrt{\frac{(6.67*10^{-11})(6.42*10^{23})}{9.38*10^6} }[/tex] and we get that
v = 2100 m/s
Now for the circumference:
C = 2πr and
C = 2(3.1415)(9.38 × 10⁶) so
C = 5.9 × 10⁷
Putting that all together in the C = vT equation:
5.9 × 10⁷ = 2100T so
T = 2.8 × 10⁴ sec or 7.8 hours
Why is velocity proportial to pressure?
Answer:
Pressure and velocity are inversely proportional to each other because if pressure increase, the velocity decrease to keep the algebraic sum of potential energy, kinetic energy and pressure constant.
Why does the weight of a body differ on different celestial bodies of the universe?
the weight of a body is 420 newton.calculate it's mass
Answer:
42g
Explanation:
the mass of a body is given by
m=weight/gravity
=420/10
=42
I hope this helps
By how many times will the kinetic energy of a body increase if its speed is tripled? Show by calculation .
Answer:
9 lần
Explanation:
Answer:
Kinetic energy (k.e) varies directly as v² from the formula
K.E=(mv²/2)
if v=3 then K.e =v²=(3)²=9
If the box of 500N is placed over the land of area of 2m²,what pressure is experted by the box on the land?
Answer:
250 Pa or N/m^2
Explanation:
Pressure(P)=F/A=500/2=250 Pa or N/m^2
what is the role of the communicator in a dc generator?
A) it keeps the electric current flowing in one direction
B) it keeps the magnetic fields of the permanent magnet steady
C) it causes the magnetic fields of the permanent magnets to reverse
D) it causes the electric current to constantly reverse its direction
Answer:
C
Explanation:
Answer:
A)
Explanation:
it keeps the electric current flowing in one direction
A certain superconducting magnet in the form of a solenoid of length 0.28 m can generate a magnetic field of 7.0 T in its core when its coils carry a current of 80 A. The windings, made of a niobium-titanium alloy, must be cooled to 4.2 K. Find the number of turns in the solenoid.
Answer:
The number of turns in the solenoid is 19506.
Explanation:
Length of solenoid, L = 0.28 m
Magnetic field, B = 7 T
Current, I = 80 A
Let the number of turns is N.
The formula used to find the magnetic field is
[tex]B = \frac{\mu 0N I}{L}\\\\7 = \frac{4 \times 3.14\times 10^{-7}\times N\times 80}{0.28}\\\\N = 19506[/tex]
what is the relation between centre of gravity and stability
Explanation:
tilting it will raise the height of its center of gravity.
define 1 second time
Answer:
define 1 second time
One second is the time that elapses during 9,192,631,770 (9.192631770 x 10 9 ) cycles of the radiation produced by the transition between two levels of the cesium 133 atom. ... One second is equal to 1/86,400 of a mean solar day.
Answer:
One part of 86400 part of a day is called one second time.
✌✌✌✌
why is the fuse used in a circuit called safety fuse?
Answer:
The maximum current which can flow through a fuse without melting it, is called its rating. ... If current higher than 8 A flows through the fuse, it would melt and circuit gets broken. ... Hence, fuse acts as a safety device
Answer:
The guy above me is right
Explanation:
pete walks at a rate of 4.0 miles per hour for 30 minutes. How far did he walk?
define simple machine
Answer:
simple machine, any of several devices with few or no moving parts that are used to modify motion and the magnitude of a force in order to perform work. ... The simple machines are the inclined plane, lever, wedge, wheel and axle, pulley, and screw.
Two forces whose resultant is 100N are at right angle to eachother. if one of them makes an angle of 30° with the resultant, determine its magnitude
Let F₁ and F₂ denote the two forces, and R the resultant force.
F₁ and F₂ point perpendicularly to one another, so their dot product is
F₁ • F₂ = 0
We're given that one of these vectors, say F₁, makes an angle with R of 30°, so that
F₁ • R = ||F₁|| ||R|| cos(30°)
But we also have
F₁ • R = F₁ • (F₁ + F₂) = (F₁ • F₁) + (F₁ • F₂) = F₁ • F₁ = ||F₁||²
So, knowing that ||R|| = 100 N, we get that
(100 N) ||F₁|| cos(30°) = ||F₁||²
(100 N) cos(30°) = ||F₁||
||F₁|| ≈ 86.6 N
(And the same would be true for F₂.)
Those of you who have recently finished high school physics-did you struggle? If you did, where did you most struggle in? Was it the tests? Or a specific topic?
Thank you!
Answer:
I'm over halfway through it so don't have a complete answer but i think you just need to keep ontop of everything and write down all the key equations on flashcards or something and aim to learn them at the beginning of each topic. i found the longer questions hard so recommend practising those
Explanation:
The plane of a5cm*8cm rectangular loop of wire is parallel to a 0.19T magnetic field the loop carries a current of 6.2 A. What torque acts on aloop? What is the magnetic moment of the loop?
Answer:
Torque; τ = 4.712 × 10^(-3) J
Magnetic moment; M = 0.0248 J/T
Explanation:
Torque is gotten from the formula;
τ = BIA
Where;
B is magnetic field
I is current
A is area
We are given;
B = 0.19T
I = 6.2A
Rectangle dimensions = 5cm by 8cm = 0.05m by 0.08m
Thus;
Area; A = 0.05m × 0.08m = 0.004 m²
Thus;
τ = 0.19 × 6.2 × 0.004
τ = 4.712 × 10^(-3) J
Formula for the magnetic moment is given by;
M = IA
M = 6.2 × 0.004
M = 0.0248 J/T
The unit of work in terms of Newton and metre is _______
Answer:
Joule
Explanation:
the unit of work is Joule determined by the letter J.
Answer:
JouleExplanation:
Joule is defined as the work done by a force of one newton causing a displacement of one meter. Sometimes, newton-metre (N-m) is also used for measuring work.
Convert 400 mm to m using the method of dimensional analysis
Answer:
To convert 400 mm to m you can apply the formula [m] = [mm] / 1000; use 400 for mm. Thus, the conversion 400 mm m is the result of dividing 400 by 1000. 0.4
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If the final velocity is 0. third equation of motion will be
Answer:
vf²=vi²+2a∆x
Explanation:
The third equation of motion gives the final velocity of an object under uniform acceleration given the distance traveled and an initial velocity: v 2 = v 0 2 + 2 a d . v^2=v_0^2+2ad. v2=v02+2ad. The graph of the motion of the object.
Ag,Au and Cu are called coinage metals why plzzzz hurry its urgent plzzz
Answer:
This is because these metals are used for minting (making) coins.
Answer:
It is bcz it is used for making coins
What is 98.907 rounded to 1 significant figure?
The answer to the digits rounded to one significant figure is 100.
Significant figures are the most important figures in a number of digits.
The closer a digit is to the beginning of a number, the more important or significant it is.
But, the rule for rounding up a set of numbers to the first significant or to one significant figure is that:
If the next number is 5 or more, we round up.If the next number is 4 or less, we do not round up.From the numbers 98.907, 9 is the most significant digit followed by 8.
8 is greater than 5 so we should round up by adding one to 9 making the number 100.
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why is it important to have regular super vision of the weights and the measurements in the market?
Answer:
Obeying to weights & measurement regulations in both national and international metrology legislation, standards and test procedures is a requirement to participate in any market because it's aimed to safeguard the consumers and promote fair competition, which provides efficiency and saves unnecessary costs to U.S. businesses and stakeholders.
Explanation:
In the U.S., the National Institute of Standards and Technology (NIST) has an Office of Weights and Measures (OWM) that represents the country in the International Organization of Legal Metrology (OIML)
Which statement best describes the arrangement of electrons in an atom of fluorine (F)?
(1 point) giving brainliest for sure
There are two electrons in the first energy level and seven electrons in the second energy level.
There are two electrons in the first energy level and five electrons in the second energy level.
There are five electrons in the first energy level and two electrons in the second energy level.
There are seven electrons in the first energy level and two electrons in the second energy level.
Flourine is an element which has 9 electrons. The first energy level can only hold upto 2 electrons so therefore two electrons of the fluorine element will be in the first orbital.
In the second orbital there will be seven electrons. The configuration will be as 1s2, 2s2 , 2p5 .
The first orbital has capacity of two electrons and then the remaining two electrons will be in higher second energy level.
The further 5 electrons will be in lower second energy level which is denoted by p.
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Answer:
#1. 5
#2.They have valence electrons in the same energy level.
#3. Helium atoms have 2 valence electrons, while atoms of the other elements in the group all have 8 valence electrons.
#4. cesium (Cs)
#5. There are two electrons in the first energy level and seven electrons in the second energy level.
Explanation:
Rearrange this equation so it equals d
v=dt
Answer:
Below
Explanation:
To solve for d rearrange the formula v = (d)(t) to:
d = v / t
I'm not to sure if you are using different variables but usually in physics the formula for velocity is v = d / t not v = dt
If you wanted to solve for displacement you would do:
d = (v)(t)
Hope this helps!
