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
slava [35]
3 years ago
12

A copper wire of 1-m length and 1-mm radius has a resistance of 5.5 × 10 − 3 [Ω] and carries a current of 4 [A]. The number of f

ree electrons per unit volume in copper is 8.43 × 10 28 [m − 3 ]. Find (a) the current density, (b) the conductivity of the copper, (c) the power dissipated in the wire, (d) the (average) drift velocity of free electrons, and (e) the mobility of free electrons.
Physics
1 answer:
SOVA2 [1]3 years ago
8 0

Answer: a)1.27 *10^6 A/m^2; b) 57.9*10^6 Ω*m; c) 94.16*10^-6 m/s;

d) 4.29*10^-3 m^2/V*s

Explanation: In order to explain this problem we have to take into account the following expressions:

The current density is equal:

J=I/A  where A is the area of the wire.

J=4A/(π*1*10^-6m^2)=1.27 *10^6 A/m^2

The resistence of the wire is given by:

R=L/(σ*A) where σ and L are the conductivity and the length of the wire, respectively.

Then we have:

σ= L/(R*A)=1/(5.5*10^-3*π*1*10^-6)=57.9 *10^6 Ω*m

The drift velocity of free electrons is given by:

Vd=i/(n*A*e) where n is the numer of electrons per volume. e is the electron charge.

then we have:

Vd=J/(n*e)= 1.27 *10^6/(8.43*10^28*1.6*10^-19)=94.16 *10^-6 m/s

Finally, the mobility of free electrons is equal to:

μ=Vd/E  ;  E=J/σ

μ=E*σ/J= 94.16*10^-6*57.9 *10^6/1.27 *10^6=4.29*10^-3 m^2/V*s

You might be interested in
Is it possible to be moving but not be in motion?
GREYUIT [131]

No. Motion is the thing that when you're moving, you're in it.

But it IS possible for one person to say you're moving and another person to say you're not moving, both at the same time, and both of them are correct !

4 0
2 years ago
Read 2 more answers
An electric generator transforms mechanical energy into electrical energy. This process could be done by which of these?
Dimas [21]

Answer:

its d

Explanation:

6 0
3 years ago
Read 2 more answers
When do net force is applied to a moving object it still comes to rest because of its inertia
Paraphin [41]
That is false for that.
6 0
3 years ago
A basketball player is 4.22 m from
max2010maxim [7]

Answer: The height above the release point is 2.96 meters.

Explanation:

The acceleration of the ball is the gravitational acceleration in the y axis.

A = (0, -9.8m/s^)

For the velocity we can integrate over time and get:

V(t) = (9.20m/s*cos(69°), -9.8m/s^2*t + 9.20m/s^2*sin(69°))

for the position we can integrate it again over time, but this time we do not have any integration constant because the initial position of the ball will be (0,0)

P(t) = (9.20*cos(69°)*t, -4.9m/s^2*t^2 + 9.20m/s^2*sin(69°)*t)

now, the time at wich the horizontal displacement is 4.22 m will be:

4.22m = 9.20*cos(69°)*t

t = (4.22/ 9.20*cos(69°)) = 1.28s

Now we evaluate the y-position in this time:

h =  -4.9m/s^2*(1.28s)^2 + 9.20m/s^2*sin(69°)*1.28s = 2.96m

The height above the release point is 2.96 meters.

3 0
2 years ago
Read 2 more answers
What is the name of the space telescope in low earth orbit that was launched in 1990?
Mrrafil [7]

The Hubble Space Telescope is a joint ESA/NASA project and was launched in 1990 by the Space Shuttle mission STS-31 into a low-Earth orbit 569 km above the ground. During its lifetime Hubble has become one of the most important science projects ever. Hope this helps! ~ Autumn :)

4 0
3 years ago
Other questions:
  • What group tend to take on electrons in order to become stable
    13·1 answer
  • If you double the dimensions of a cube what happens to the volume
    11·1 answer
  • The particles of a medium will settle the rest position after a mechanical wave passes
    13·2 answers
  • A 6kg object speeds up from 5 m/s to 20 m/s. find p
    11·2 answers
  • A capacitor with plates separated by a distance d is charged to a potential difference ΔVC. All wires and batteries are disconne
    13·1 answer
  • A hole is drilled in a metal plate. When the metal is raised to a higher temperature, what happens to the diameter of the hole?
    15·1 answer
  • What is the frequency of a wave having a period Equal to 18 seconds
    6·1 answer
  • Anne should use a to transfer electric energy into motion. She should also use a to start and stop the flow of current.
    15·1 answer
  • An air bubble at the bottom of a lake 52.0 m deep has a volume of 1.50m^3. If the temperature at the bottom is 5.5 degree's Cels
    15·1 answer
  • Type in the correct values to correctly represent the valence electron configuration of oxygen: AsB2pC A = B = C = What is the c
    13·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!