1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
VladimirAG [237]
3 years ago
8

Which is true regarding AC current? The electrons move back and forth. The +/- polarity is constant. It is common in portable de

vices. It can only produce low voltages.
Physics
2 answers:
Rus_ich [418]3 years ago
8 0
A. The electrons move back and forth.
Hope this helped. :L
andre [41]3 years ago
7 0

Answer: Option (a) is the correct answer.

Explanation:

AC current stands for alternating current. In an alternating current there is periodically reverse movement of current.

This means electrons move in one direction for a certain time and then they reverse their movement for the same time period and it continues in the back and forth position.

Thus, we can conclude that the statement electrons move back and forth is true regarding AC current.


You might be interested in
A rifle fires a 2.90 x 10-2-kg pellet straight upward, because the pellet rests on a compressed spring that is released when the
iren2701 [21]

Answer: 586.60N/m

Explanation:

In this scenario, the elastic potential energy of the spring is converted into potential energy.

0.5*K*x^2 = mgh

Thus K = 2mgh/x^2

=(2*2.90*10^-2*9.8*7.23)/(8.37*10^-2)^2

=586.599

Therefore K = 586.60N/m

7 0
3 years ago
Read 2 more answers
a man checked himself into seattle hospital. he didnt know who he was and had no idea how he got to seattle. the hospital staff
8090 [49]

Amnesia would be the answer

7 0
3 years ago
Read 2 more answers
Compute the torque about the origin of the gravitational force F--mgj acting on a particle of mass m located at 7-xî+ yj and sho
Andrews [41]

Answer:

Explanation:

Force, F = - mg j

r = - 7x i + y j

Torque is defined as the product f force and the perpendicular distance.

It is also defined as the cross product of force vector and the displacement vector.

\overrightarrow{\tau }=\overrightarrow{r}\times \overrightarrow{F}

\overrightarrow{\tau }=(- 7 x i + yj)\times (-mgj)

[tex]\overrightarrow{\tau  }= 7 m g x k

Here, we observe that the torque is independent of y coordinate.

3 0
3 years ago
Calculate curls of the following vector functions (a) AG) 4x3 - 2x2-yy + xz2 2
aleksandr82 [10.1K]

Answer:

The curl is 0 \hat x -z^2 \hat y -4xy \hat z

Explanation:

Given the vector function

\vec A (\vec r) =4x^3 \hat{x}-2x^2y \hat y+xz^2 \hat z

We can calculate the curl using the definition

\nabla \times \vec A (\vec r ) = \left|\begin{array}{ccc}\hat x&\hat y&\hat z\\\partial/\partial x&\partial/\partial y&\partial/\partial z\\A_x&X_y&A_z\end{array}\right|

Thus for the exercise we will have

\nabla \times \vec A (\vec r ) = \left|\begin{array}{ccc}\hat x&\hat y&\hat z\\\partial/\partial x&\partial/\partial y&\partial/\partial z\\4x^3&-2x^2y&xz^2\end{array}\right|

So we will get

\nabla  \times \vec A (\vec r )= \left( \cfrac{\partial}{\partial y}(xz^2)-\cfrac{\partial}{\partial z}(-2x^2y)\right) \hat x - \left(\cfrac{\partial}{\partial x}(xz^2)-\cfrac{\partial}{\partial z}(4x^3) \right) \hat y + \left(\cfrac{\partial}{\partial x}(-2x^2y)-\cfrac{\partial}{\partial y}(4x^3) \right) \hat z

Working with the partial derivatives we get the curl

\nabla  \times \vec A (\vec r )=0 \hat x -z^2 \hat y -4xy \hat z

6 0
3 years ago
Two 25.0N weights are suspended at opposite ends of a rope that passes over a frictionless pulley. What is the tension in the ro
goldenfox [79]

Answer:

tension in rope = 25.0 N

Explanation:

  • Two forces act on the suspended weight. The force coming down is the gravitational force and the upward force by the tension in the rope.
  • Since the suspended weight is not accelerating so that the net force will be zero. Therefore the tension in the rope should be 25 N.

       ∑F = F - W = 0

       so

       F = W

       so tension in rope = F  = T  = 25 N

8 0
3 years ago
Other questions:
  • A cylinder with moment of inertia I about its center of mass, mass m, and radius r has a string wrapped around it which is tied
    5·1 answer
  • What units are used to measure force
    7·2 answers
  • What do telescopes detect that assists astronomers making discoveries in space
    14·1 answer
  • Lightning occurs when there is a flow of electric charge (principally electrons) between the ground and a thundercloud. The maxi
    15·1 answer
  • Evangelista Torricelli was the first person to realize that we live at the bottom of an ocean of air. He correctly surmised that
    14·1 answer
  • 10Ω resistor and a 5 Ω are connected in parallel. This pair is then connected in series in with another 4 Ω resistor. What is th
    14·1 answer
  • A car is travelling at a constant speed of 26.5 m/s. Its tires have a radius of 72 cm. If the car slows down at a constant rate
    7·1 answer
  • Two loudspeakers are placed 1.8 m apart. They play tones of equal frequency. If you stand 3.0 m in front of the speakers, and ex
    15·1 answer
  • <img src="https://tex.z-dn.net/?f=See%20%5C%3A%20%20Attachment.%20%20%5C%3A%20" id="TexFormula1" title="See \: Attachment. \:
    14·2 answers
  • A juggler throws two balls to the same height so that one is at the halfway point going up when the other is at the halfway poin
    11·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!