Electrons do not move unless they are attracted to an electromagnet <br><br> True or false

A box on a ramp is connected by a rope to a winch. The winch is turned so that the box moves down the ramp at a constant speed.

Marrrta [24]

Answer:

Option B:

The normal force

Explanation:

The normal force does no work as the box slides down the ramp.

Work can only be done when the force succeeds in moving the object in the direction of the force.

All the other forces involved have a component that is moving the box in their direction.

However, the normal force does not, as it points downwards into the ramp. Since the normal force is pointing into the ramp, and the box is sliding down the ramp, we can say that no work is being done by the normal force because the box is not moving in its direction (which would have been the box moving into the ramp)

7 0

4 years ago

What is all matter made up of?

aliya0001 [1]

All matter is made up of atoms

3 0

4 years ago

Read 2 more answers

An object having a fixed emissivity of 0. 725 radiates heat at a rate of 10 w when it is at an absolute temperature t. If its te

koban [17]

If the temperature is doubled to 2t, the rate at which it will now radiate is 160 W.

<h3>What is meant by emissivity?</h3>

The ability of a substance to reflect heat radiation from its surface is measured by its emissivity.
Thermal radiation is a type of electromagnetic radiation that includes infrared radiation, which the human eye cannot perceive, as well as visible radiation (light).
According to the Stefan-Boltzmann law, emissivity is the quantitative comparison between the thermal radiation of a surface and that of an ideal black surface at a given temperature.
Between 0 and 1 is the ratio's range.

<h3>What is energy radiation?</h3>

The emissivity of a substance is a measurement of how well it reflects heat radiation from its surface.
Two elements that affect power dissipation in the form of radiation are the material's surface emissivity and the temperature difference between the chip surface and the surrounding air.

To learn more about emissivity visit:

brainly.com/question/14279657

#SPJ4

8 0

1 year ago

A student is experimenting with some insulated copper wire and a power supply. She winds a single layer of the wire on a tube wi

OverLord2011 [107]

Answer:

$P=214.7187\,W$

Explanation:

Given that:

Diameter of the solenoid, $D=10\,cm=0.1\,m$

length of the solenoid, $L=90\,cm=0.9\,m$

diameter of the wire, $d=0.1\,cm=10^{-3}\,m$

magnetic field at the center of the solenoid, $B=7.4\times 10^{-3}\,T$

<u>Now we need the no. of turns incorporated in the length of 90 cm:</u>

$N=\frac{Length\,\,of\,\,solenoid}{diameter\,\,of\,\, wire}$

$N=\frac{L}{d}$

$N=\frac{0.9}{10^{-3}}$

$N=900\,\,turns$

For solenoids we have:

$B=\mu.n.I$ ...............................(1)

where:

$\mu=$ permeability of the medium

n = no. of turns per unit length

I = current in the coil

So,

$n=\frac{900}{0.9}$

$n=1000\,turns\,.\,m^{-1}$

Now putting the respective values in the eq. (1)

$7.4\times 10^{-3}=4\pi\times10^{-7}\times 1000\times I$

$I=5.8887\,A$

For copper we have resistivity:

$\rho=1.72\times 10^{-8}\, \Omega.m$

We know that resistance is given by:

$R=\rho.\frac{l}{a}$ .....................................(2)

where:

l = length of the conducting wire

a = cross sectional area of the conducting wire

<u>Now we need the length (l) of the wire:</u>

Circumference of the solenoid,

$C=\pi.D$

$C=0.1\pi\,m$

$\therefore l=C\times N$

$l=90\pi\,m$

&

<u>Cross-sectional area of wire:</u>

$a=\pi.\frac{d^2}{4}$

$a=\pi. \frac{(10^{-3})^2}{4}\,m^2$

<u>Resistance from eq. (2):</u>

$R=1.72\times 10^{-8}\times \frac{90\pi}{\pi. \frac{(10^{-3})^2}{4}}$

$R=6.192 \,\Omega$

For power we have:

$P=I^2.R$

$P=5.8887^2 \times 6.192$

$P=214.7187\,W$

6 0

3 years ago

Technetium (Tc; Z = 43) is a synthetic element used as a radioactive tracer in medical studies. A Tc atom emits a beta particle

LenKa [72]

Answer : The de-Broglie wavelength of this electron, $0.101\AA$

Explanation :

The formula used for kinetic energy is,

$K.E=\frac{1}{2}mv^2$ ..........(1)

According to de-Broglie, the expression for wavelength is,

$\lambda=\frac{h}{mv}$

or,

$v=\frac{h}{m\lambda}$ ...........(2)

Now put the equation (2) in equation (1), we get:

$\lambda=\frac{h}{\sqrt{2\times m\times K.E}}$ ...........(3)

where,

$\lambda$ = wavelength = ?

h = Planck's constant = $6.626\times 10^{-34}Js$

m = mass of electron = $9.11\times 10^{-31}Kg$

K.E = kinetic energy = $4.71\times 10^{-15}J$

Now put all the given values in the above formula (3), we get:

$\lambda=\frac{6.626\times 10^{-34}Js}{\sqrt{2\times 9.11\times 10^{-31}Kg\times 4.71\times 10^{-15}J}}$

$\lambda=1.0115\times 10^{-11}m=0.101\AA$

conversion used : $(1\AA=10^{-10}m)$

Therefore, the de-Broglie wavelength of this electron, $0.101\AA$

7 0

3 years ago

Electrons do not move unless they are attracted to an electromagnet True or false