Answer:
The north pole of an electromagnet placed in the center of a permanent magnet repels the north pole of the permanent magnet.
Explanation:
The commutator of the electric motor reverses the current in each half revolution to keep the torque, turning the coil in the same direction. This occurs as the north pole of the electromagnet nears the south pole of the permanent magnet, and the current reverses, which causes the poles of the magnets to repel.
Thus, the correct answer is "the north pole of an electromagnet placed in the center of a permanent magnet repels the north pole of the permanent magnet".
Answer:
The answer is D
Explanation:
Just took the test on Edge :)
A material that reflects or absorbs all the light that strikes it is
A. opaque.
B. transparent.
C. translucent.
D. primary.
Answer:
b. transparent
Explanation:
Photons interact with an object by some combination of reflection, absorption and transmission. Some materials, such as plate glass and clean water, transmit much of the light that falls on them and reflect little of it; such materials are called optically transparent.
Select the correct answer.
Which of Newton's laws explains why your hands get red when you press them hard against a wall?
ОА.
Newton's law of gravity
OB.
Newton's first law of motion
O c.
Newton's second law of motion
OD.
Newton's third law of motion
Answer:
D. Newton's third law of motion
What is the magnetic field strength at a point 2.5 mm radially from the center of the wire leading to the capacitor
Complete Question
A 8.0 A current is charging a 1.0 -cm-diameter parallel-plate capacitor. What is the magnetic field strength at a point 2.5 mm radially from the center of the wire leading to the capacitor?
Answer:
The magnetic field is [tex]B = 6.4*10^{-4} \ T[/tex]
Explanation:
From the question we are told that
The current is [tex]I = 8.0 \ A[/tex]
The diameter is [tex]d = \ cm = \frac{1}{100} = 0.01 m[/tex]
The position considered is [tex]d = 2.5 \ mm = 0.0025 \ m[/tex]
Generally the magnetic field is mathematically represented as
[tex]B = \frac{\mu_o * I }{ 2 \pi d}[/tex]
Here [tex]\mu_o[/tex] is permeability of free space with value
[tex]\mu_o = 4\pi * 10^{-7} \ N/A^2[/tex]
So
[tex]B = \frac{ 4\pi * 10^{-7} * 8 }{ 2 \pi * 0.0025 }[/tex]
=> [tex]B = \frac{ 2 * 10^{-7} * 8 }{ * 0.0025 }[/tex]
=> [tex]B = 6.4*10^{-4} \ T[/tex]
What causes the Earth's spherical shape
Answer:
spherical shape
Explanation:
The Earth is massive enough that the pull of gravity maintains its roughly spherical shape. Most of its deviation from spherical stems from the centrifugal force caused by rotation around its north-south axis. This force deforms the sphere into an oblate ellipsoid.
Acceleration and force are proportional
Answer:
whats the question tho
The components of vectors A and B are given as follows:
Ax = 7.6
Bx = -5.1
Ay = -9.2
By = -6.8
What is the magnitude of the vector difference B - À?
Answer:
|B - A| = 12.92 units
Explanation:
In order to find the magnitude of B-A vector, we first write A and B in Vector Notation:
A = Aₓ i + Ay j
A = 7.6 i - 9.2 j
B = Bₓ i + By j
B = -5.1 i - 6.8 j
So, there difference will be:
B - A = (-5.1 i - 6.8 j) - (7.6 i - 9.2 j)
B - A = -12.7 i + 2.4 j
Now, the magnitude of this vector can be found out by using the formula:
|B - A| = √[(x-component)² + (y-component)²]
|B - A| = √[(-12.7)² + (2.4)²]
|B - A| = 12.92 units
We will see that the magnitude of the difference of the vectors is 12.92
How to get the difference of two vectors?
Here we have two vectors:
A = <7.6, -9.2>
B = <-5.1, -6.8>
To get the difference we just subtract the correspondent components:
B - A = <Bx - Ax, By - Ay> = <-5.1 - 7.6, -6.8 - (-9.2)> = <-12.7, 2.4>
The magnitude of that vector is just:
[tex]M = \sqrt{(2.4)^2 + (-12.7)^2} = 12.92[/tex]
If you want to learn more about vectors, you can read:
https://brainly.com/question/4889980
what is simple machine? write any four advantages if it
Answer: See explanation
Explanation:
Simple machine is a machine that has few moving parts or may also have no moving parts and they are usually used to make ones work easier. Examples include wheel and axle, wedge, pulley, lever, screw or an inclined plane.
Their advantages include:
• Less energy is required to perform a particular work.
• It makes work easier.
• It makes work faster.
• Simple machine enable one to do things that might have been difficult to achieve or do.
a ship sonar sends message and recives the eschoes from the ocean bottom 0.6 second after the sound is sent down the ship how deep is the water beneath the ship
Answer: 600 feet
Explanation:
I need help
Pls for me
If you push against the wall the wall will push back what is the name of the force that pushes back?
tension force
Оа
Ob
Ос
normal force
applied force
friction force
Od
Answer:
applied force
Explanation:
I think that's right
A 4-foot spring measures 8 feet long after a mass weighing 8 pounds is attached to it. The medium through which the mass moves offers a damping force numerically equal to 2 times the instantaneous velocity. Find the equation of motion if the mass is initially released from the equilibrium position with a downward velocity of 3 ft/s. (Use g
Answer:
[tex]\mathbf{x = 3te ^{-2 \sqrt{2t}}}[/tex]
Explanation:
From the given information concerning the spring-mass system:
Let us apply Hooke law.
Then, we have:
mg = ks
8 = k4
k = 8/4
k = 2
Provided that the mass weighing 8 lbs is attached to a spring.
Then, we can divide it by gravity 32 ft/s².
∴
m = 8/32
m = 1/4 slugs
The medium that offers the damping force [tex]\beta = \sqrt{2}[/tex]
Now, let us set up a differential equation that explains the motion of the spring-mass system.
The general equation is:
[tex]mx '' + \beta x' + kx = 0[/tex]
where;
[tex]m = \dfrac{1}{4}[/tex]
k = 2, and
[tex]\beta = \sqrt{2}[/tex]
Then;
[tex]\dfrac{1}{4}x'' + \sqrt{2} x' + 2x = 0[/tex]
By solving the above equation, the auxiliary equation is:
[tex]m^2 + 4 \sqrt{2} m + 8n = 0[/tex]
Using quadratic formula:
[tex]\dfrac{-b \pm \sqrt{b^2 -4ac}}{2a}[/tex]
[tex]m = \dfrac{-4 \sqrt{2} \pm \sqrt{(4 \sqrt{2})^2 -4(1)(8) }}{2}[/tex]
[tex]m = \dfrac{-4 \sqrt{2} \pm \sqrt{32 -32 }}{2}[/tex]
[tex]m = -2 \sqrt{2}[/tex]
Since this is a repeated root, the solution to their differential equation took the form.
[tex]x_c = c_1 e^{mt} + c_2 t e^{mt}[/tex]
[tex]x_c = c_1 e^{-2\sqrt{2} t} + c_2 t e^{-2\sqrt{2} t}[/tex]
From the initial condition.
At equilibrium position where the mass is being from:
x(0) = 0
Also, at the downward velocity of 3 ft/s
x'(0) = 3
Then, at the first initial condition:
[tex]x_c (0) = c_1 e^{-2\sqrt{2} *0} + c_2 (0) e^{-2\sqrt{2} *0}[/tex]
[tex]0= c_1 e^{0} + 0[/tex]
[tex]0= c_1[/tex]
At the second initial condition;
[tex]x' = -2 \sqrt{2} c_1 e^{-2 \sqrt{2} t } -2 \sqrt{2} c_2 t e^{-2 \sqrt{2} t } + c_2 e^{-2 \sqrt{2} t}[/tex]
where;
x'(0) = 3
[tex]x' (0) = -2 \sqrt{2} c_1 e^{-2 \sqrt{2}* 0 } -2 \sqrt{2} c_2 (0) e^{-2 \sqrt{2} *0 } + c_2 e^{-2 \sqrt{2} *0}[/tex]
[tex]3 = -2 \sqrt{2} * 0 *e^0 - 0 + c_2 e^0[/tex]
[tex]3 = 0 + c_2[/tex]
[tex]3 = c_2[/tex]
Replacing in the constraints, the equation of the motion is:
[tex]\mathbf{x = 3te ^{-2 \sqrt{2t}}}[/tex]
who win tug of war with what net force
Answer:
The force on rope is equal for both of them at any time.
For winning the game the force on ground is responsible.
Explanation:
How do gamma rays use electromagnetic waves to function....PLS HELP
Answer:
Gamma-rays have the smallest wavelengths and the most energy of any other wave in the electromagnetic spectrum. These waves are generated by radioactive atoms and in nuclear explosions.
Explanation:
Gamma-rays can kill living cells, a fact which medicine uses to its advantage, using gamma-rays to kill cancerous cells.
Hope this helps!
Brain-LIst?
Centripetal forces are always directed toward the (center, outside) of a circle.
Answer:
Centripetal forces are directed toward the center of a circle.
Hope this helps.
Explanation:
The force needed to move a body in a curved way is understood as centripetal force. Centripetal forces are always directed toward the center of a circle.
What is centripetal force?The force needed to move a body in a curved way is understood as centripetal force. This is a force that can be sensed from both the fixed frame and the spinning body's frame of concern.
The direction of centripetal force is always in the path of the center of the course.
Hence center is the right option. Centripetal forces are always directed toward the center of a circle.
To learn more about the centripetal force refer to the link;
https://brainly.com/question/10596517
What are electromagnetic waves?
Answer:
Electromagnetic waves or EM waves are waves that are created as a result of vibrations between an electric field and a magnetic field. In other words, EM waves are composed of oscillating magnetic and electric fields. They are also perpendicular to the direction of the EM
Explanation:
What single resistor could replace 20 Ω, 30 Ω and 50 Ω resistors which have been joined in series ?
Answer:
sine the resistors are connected in series, we could add the sum and that single value replaces the individual resistors in series. therefore, 100ohm resistor can do.
A mouse is running across a room with a speed of 2.2 m/s. The mass of the mouse is 1.4 kg. What is the Kinetic Energy of the mouse?
Answer:
3.39 JExplanation:
The kinetic energy of an object can be found by using the formula
[tex]k = \frac{1}{2} m {v}^{2} \\ [/tex]
m is the mass
v is the velocity
From the question we have
[tex]k = \frac{1}{2} \times 1.4 \times {2.2}^{2} \\ = 0.7 \times 4.84 \\ = 3.388 \: \: \: \: \: \: \: \: \: [/tex]
We have the final answer as
3.39 JHope this helps you
Answer:
im not sure
Explanation:
4. A massless spring hangs from the ceiling, and a mass is hung from the bottom of it. The mass is supported
so that initially the tension in the spring is zero. The mass is then suddenly released. At the bottom of
its trajectory, the mass is 5 centimeters from its original position. Find its oscillation period.
(A) 0.05 s
(B) 0.07 s
(C) 0.31 s
(D) 0.44 s
(E) Not enough information is given.
Answer:
The correct option is C: 0.31 s.
Explanation:
When the mass is then suddenly released we have:
[tex] F = k\Delta y [/tex]
Where:
F is the force
k: is the spring constant
Δy: is the spring displacement
Since the tension in the spring is zero, the force is the weight:
[tex] F = mg [/tex]
Where:
m is the mass of the object
g is the gravity
[tex] mg = k\Delta y [/tex] (1)
The oscillation period of the spring is given by:
[tex] T = 2\pi \sqrt{\frac{m}{k}} [/tex] (2)
By solving equation (1) for "k" and entering into equation (2) we have:
[tex] T = 2\pi \sqrt{\frac{m}{\frac{mg}{\Delta y}}} [/tex]
[tex]T = 2\pi \sqrt{\frac{\Delta y}{g}}[/tex]
Since the spring will osclliates in a position between the initial position (when it is at rest) and the final position (when the mass is released and reaches the bottom), we have Δy = 2.5 cm = 0.025 m:
[tex] T = 2\pi \sqrt{\frac{0.025 m}{10 m/s^{2}}} = 0.31 s [/tex]
Hence, the oscillation period is 0.31 s.
The correct option is C: 0.31s.
I hope it helps you!
A sports car accelerates from 0 to 25 meters per second in 4 seconds. What is its acceleration?
Question 1 options:
10ms2
6.25 ms2
25ms
0ms
20pts
Answer:
6.25 ms²
Explanation:
..................
What kind of energy do plants convert light energy from the sun
Answer: chemical energy
Explanation:
Which two options describe physical properties of matter?
Answer:
A and E.
Explanation:
Physical properties have to do with things that are not done chemically.
A has to do with light that you can see.
B has to do with Ph (If not A this is your next answer)
C mentions a Patina which is a chemical reaction known as oxidation
D has to do with chemical reactions
E is always correct. One of the fundamental laws about matter is that it must always have mass.
I am 99% confident in A and E as your answer, but if it is wrong go with B and E.
Hope this helps!
Describe any major landmarks (buildings, bridges, historical sites, etc.) that were destroyed during the valdivia earthquake.
Answer:
Homes, Workplaces, Statues, Meuseums
Explanation:
if you did look into it you would know after the earthquake there was a tsunami which flooded alot of places, this made many homeless, jobless, and many lossing vaklueable things
Which example is most likely made from both metals and gemstones?
Answer:
A Necklace is most likely made from both metals and gemstones
Explanation:
Brainliest?
If you drop a rock from 700 meters high, how long will it take the hit the ground? (Remember to make height negative when solving because it is falling)
Answer:
it would be 11.95 seconds
Explanation:
sorry for saying i did not know
Which of these quantities is constant in uniform circular motion?
A.speed
B.Velocity
C.acceleration
D.displacement
Can you find two ways that carbon can get from the ocean to the lithosphere?
Answer:
Two ways carbon can get from the ocean to the lithosphere is through the marine plants + animals (in the ocean) , sediments, petroleum then to the lithosphere.
Hope that helps!
How fast is the runner moving between 2-3 seconds? Is the other question please help
Answer:
Concept: Physics analysis
We have a distance vs time graph That indicates that we are analyzing the distance traveled by either a person or a particle The runner starts at 4 meters and over the interval of a second runs to 12 meters reaching the 16 meter mark. The runner stood at 16 meter mark for one full second and then runs back 10 meter over the course of one second reaching 6 meter. The runner runs forward again for a second traveling 6 meters, ending at the 12 meter mark.g calculate the effectiveness radiation dosage in sieverts for a 79 kg person who is exposed 6.8x10^9
Answer:
The answer is "[tex]\bold{dosage = 0.031 rem}[/tex]"
Explanation:
please find the complete question in the attached file.
Given value:
[tex]m = 79\ kg \\\\n = 3.4 \times 10^9 \\\\E = 5.5 \times 10^{-13} \\\\ RBE = 15[/tex]
[tex]\to E = n E\\[/tex]
[tex]= 3.4 \times 10^9 \times 5.5 \times 10^{-13} \\\\ = 1.87 \times 10^{-3}[/tex]
[tex]\to E(absorbed) = 1.87 \times 10^{-3} \times 0.87 = 1.63 \times 10^{-3}[/tex]
calculating the radiation absorbed per kg:
[tex]= \frac{1.63 \times 10^{-3}}{79} \\\\ = 2.06 \times 10^{-5} \\\\ = 0.00206 \ rad[/tex]
[tex]\to Dosage = 0.00206 \times 15 \\[/tex]
[tex]= 0.031 \ \ rem[/tex]
An electromagnetic wave of wavelength 435 nm is traveling in vacuum in the —z direction. The electric field has an amplitude of 2.70 x 10^-3 V/m and is parallel to the x axis. What are the frequency and the magnetic-field amplitude of this wave? In calculating the amplitude of the magnetic field, you divide the electric-field amplitude by the speed of light, which requires you to convert some units. Which of the following is equivalent to 1 T?
a. 1 (N/A.m)
b. 1 (N/c.m)
c. 1 (N.s/C.m)
d. 1 (V.s/m^2)
Answer:
a) 6.9*10^14 Hz
b) 9*10^-12 T
Explanation:
From the question, we know that
435 nm is given as the wavelength of the wave, at the same time, we also know that the amplitude of the electric field, E(max) has been given to be 2.7*10^-3 V/m
a)
To find the frequency of the wave, we would be applying this formula
c = fλ, where c = speed of light
f = c/λ
f = 3*10^8 / 435*10^-9
f = 6.90*10^14 Hz
b) again, to find the amplitude of the magnetic field, we would use this relation
E(max) = B(max) * c, magnetic field amplitude, B(max) =
B(max) = E(max)/c
B(max) = 2.7*10^-3 / 3*10^8
B(max) = 9*10^-12 T
c) and lastly,
1T = 1 (V.s/m^2)
Suppose a square wave signal has a 65 percent duty cycle and an on-state voltage of 40 volts DC. What is the average DC voltage
Answer:
The voltage is [tex]\= DC _v = 2.6 \ V[/tex]
Explanation:
From the question we are told that
The duty cycle is p = 65% = 0.65
The on - state voltage is [tex]V = 40 \ volt[/tex]
Generally the average DC voltage is mathematically represented as
[tex]\= DC _v = p * V[/tex]
=> [tex]\= DC _v = 40 * 0.65[/tex]
=> [tex]\= DC _v = 2.6 \ V[/tex]