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 give negative acceleration ?
Answer:
But negative acceleration means that the rate of change of velocity is negative or velocity decreases. Example: (1) When we apply brakes in a moving car, then negative acceleration acts on it and the car stops. (2) When we throw a ball upwards, then also negative acceleration acts on it.
Explanation:
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MATHEMATICALLY A NEGATIVE ACCELERATION MEANS YOU WILL SUBTRACT FROM THE CURRENT VALUE OF THE VELOCITY.
What is not one of the main uses of springs?
A. Bike suspension
B. The seasons
C. Clock making
D. Car suspension
Quick answer
Answer:
b. the seasons
Explanation:
Please help me , I also have to show work on paper
Answer:
Choose B
Explanation:
Hope Can I help you
differniate between Magnetic force and electrostatic force
Answer:
magnetic force:
i) It is exerted by a magnet.
ii)Magnetic forces are always normal to the direction of the velocity of the charge it acts upon.
Electrostatic force
i) It is exerted by electrically charged body.
ii)Electric force are independent of the direction the charge moves in.
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is there any machine that is 100% efficient? why?why not
Answer:
No, it's not there.
Explanation:
For a machine to be 100% efficient, it has to be with an output which is equal to its input. But machines have an out put less than an input, hence efficiency below 100%.
Does water exist on Mars? Explain your answer. Why didn't Jupiter become a star during the early.
Answer:
yes water was discovered in mars
mercury is commonly used in thermometer give reasons
Answer:
hi
BECAUSE MERCURY IS USED BECAUSE IT is the only liquid available in room temperatureExplanation:
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What kind of circuit is the one shown below?
A. Series
B. Parallel
C. Open
D. Combination
That's a parallel circuit. (B)
When current from Point-A reaches the 3-way intersection just to the right of Point-B, it has to make a choice: Either turn left, go through B, and light the lower bulb, or go straight and light the upper bulb.
A circuit that has any "decision" points in it is a parallel circuit. What happens in the real world is: The current splits up. Some of the current that reaches the intersection turns left toward Point-B, and the rest of it goes straight up.
A series circuit is one in which there's only one possible path all the way around. There are no intersections of more than 2 roads, and no electron ever has to decide which way to flow.
An open circuit is one in which there's a break somewhere along the line and electrons can't jump across it. It's like a railroad where a big piece is cut out of the track somewhere. So no trains can travel on that route, and there's no current flowing anywhere in the circuit.
I'm not so sure about a "combination" circuit. I guess you could give that name to a complicated circuit that has some series parts and some parallel-parts. Personally, I'd call that a "series-parallel" circuit. But it really doesn't matter right now. Whatever the word means, the circuit in the picture is definitely not a "combination" circuit.
Answer:
B. Parallel Circuits
Explanation:
A parallel circuit is constructed by connecting the terminals of all the individual load devices so that the same value of voltage appears across each component. In a parallel circuit, charge divides up into separate branches such that there can be more current in one branch than there is in another.
hope i helped
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:
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
The mass of earth 6*10^24kg and radius is 400kg Now find the value of acceleration due to gravity when a object is 3600km from the earth surface
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 does the weight of a body differ on different celestial bodies of the universe?
Saul is testing an installation and discovers a short circuit what’s causing this
A.high current
B.high voltage
C.low resistance
D.low voltage
Answer:
im pretty sure that it's (A.) High current
Explanation:
pf
not 100% sure, tho
Robin fired a bullet of mass 100 gm from a gun of mass 5 kg. The bullet leaves the gun with a speed of 400 m/s. After penetrating 4 cm of a plank of 10 cm, the bullet loses one third of its initial velocity.
a. Calculate the backward velocity of the gun?
b. Can the bullet penetrate the plank of the wood completely? Explain mathematically.
please help
(a) The recoil or backward velocity of the gun is 8 m/s.
(b) The bullet cannot penetrate the plank of the wood completely.
The given parameters include;
mass of the bullet, m₁ = 100 g = 0.1 kgmass of the gun, m₂ = 5 kginitial velocity of the bullet, u₁ = 400 m/sthickness of the plank, x = 10 cm(a) The backward or recoil velocity of the gun is calculated by applying the principle of conservation of linear momentum.
let the backward or recoil velocity of the gun = u₂m₁u₁ + m₂u₂ = 0
m₂u₂ = -m₁u₁
[tex]u_2 = -\frac{m_1u_1}{m_2} \\\\u_2 = - \frac{0.1 \times 400}{5} \\\\u_2 = -8 \ m/s[/tex]
Thus, the recoil or backward velocity of the gun is 8 m/s.
(b) determine if the bullet can penetrate the plank of the wood completely
the bullet traveled 4 cm and lost ¹/₃ of u₁the remaining distance to completely penetrate the plank = 6 cmthe final velocity of the bullet at 4 cm, v = 400 - ¹/₃ x 400 m/s = 266.67 m/sthe acceleration of the bullet is calculated as;
v² = u₁² + 2as
2as = v² - u²
[tex]a = \frac{v^2 -u_1^2}{2s} \\\\a = \frac{(266.67)^2 -(400)^2}{2\times 0.04} = -1.111 \times 10^6 \ m/s^2[/tex]
Finally, determine the distance traveled by the bullet when it comes to a complete stop, that is the final velocity = 0
[tex]v_f^2 = v^2 + 2ad\\\\2ad = v_f^2 - v^2\\\\d = \frac{v_f^2 - v^2}{2a} \\\\d = \frac{(0) - (266.67)^2}{2(-1.111\times 10^6)} \\\\d = 0.032 \ m[/tex]
d = 3.2 cm
The total distance traveled by the bullet inside the plank = 4 cm + 3.2 cm = 7.2 cm
Therefore, the bullet cannot penetrate the plank completely.
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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.
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The direction of applied force has to be .............. to the distance in order to say work is done
Answer:
Parallel
Explanation:
The work done is defined as the force applied on an object and the displacement in the position of the object in the direction of force.
W = F s cos A
where, F is the force, s is the displacement and A is the angle between force and displacement.
When the angle between the force and the displacement is 90 degree, the work done is zero.
To get the maximum work the angle between the force and the displacement is 0 degree.
So, to get the work done by the force the angle between the force and displacement is 0 degree that means the force and displacement is parallel to each other.
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 do is mean by environment friendly behaviour?
Which of the following is a vector quantity? i. Force ii. Velocity iii. Acceleration iv. All of these 5771
Option ( iv ) is the correct answer.
☛ DefinitionA vector quantity the physical quantity that has both direction as well as magnitude.
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)
List two factors that compression force depends on
The magnitude (size or numerical value) and the direction.
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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
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.
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.)
9. Which of the following is NOT a recommendation to help you succeed in this course?
Consistently and actively work in the course on a daily basis.
Wait until the end of the semester to complete all work.
Complete all assignments in a timely manner.
Contact your instructor if you have questions.
Answer:
Wait until the end of the semester to complete all work.
Explanation:
this is the obvious answer.
please mark me brainliest
Answer:
Wait until the end of the semester to complete all work
the force between the earth and the body which is at a distance r from the center of the earth is F. What must be this distance for the force to be doubled.
Answer:
Explanation:
The gravitational force between the earth and another body is F = -GM_em/r^2 r where G = 6.67 times 10^-11 Nm^2/kg^2 is the gravitational constant, M_e = 5.97 times 10^24 kg is the mass of the earth, m is the mass of the other body, and r is the position vector of the second body with respect to the centre of the earth.
You plan to pass alpha particles through a field that contains a consistent type of particle. Which configuration will result in the largest deflection of alpha particles? (1 point)
low-energy alpha particles passing through a field of low mass-number-particles
low-energy alpha particles passing through a field of high mass-number-particles
high-energy alpha particles passing through a field of high mass-number-particles
high-energy alpha particles passing through a field of low mass-number-particles
Answer:
low-energy alpha particles passing through a field of high mass-number-particles
Answer:
low-energy alpha particles passing through a field of high mass-number-particles
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!
