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
Leno4ka [110]
3 years ago
9

How long does it take electrons to get from the car battery to the starting motor? Assume the current is 137 A and the electrons

travel through copper wire with cross sectional area 44.6 mm2 and length 75.7 cm . The mass density of copper is 8960 kg/m3 and the molar mass is 63.5 g/mol . Avogadro’s number is 6.022 × 1023 . Assume that each copper atom contributes one conduction electron. Answer in units of min.
Chemistry
1 answer:
WARRIOR [948]3 years ago
4 0

Answer:

t = 55.79 min

Explanation:

First, the problem is asking for calculate the time that it takes electrons from the battery to the motor.

The general formula to calculate time is:

<em>t = d/V (1)</em>

Where:

d: distance or length

V: speed

Now, we don't have data of speed, but we can know an expression of current density in function of the distance which is the following:

<em>J = n*q*V (2)</em>

Where:

q: charge of the particle (1.6x10^-19 C)

n: number of charge carriers per unit of volume

Current density (J) is actually current per Area so:

<em>J = I/A (3)</em>

Replacing (3) in (2) we have:

I/A = nqV

Solving for V:

<em>V = I/Anq (4)</em>

Finally, if we replace this expression in (1) we have:

<em>t = nqAd / I (5)</em>

Now, the value of n, it's not given but it can be calculated because we have mass density, molar mass and avogadro's number, so this value of "n" can be calculated using the following expression:

<em>n = D * Av / MM (6)</em>

Where:

D: mass density (kg/m³)

Av: avogadro number (6.02x10^23 atom/mol)

MM: molar mass (kg/mol)

Putting the data that we know to calculate n we have:

n = 8960 * 6.02x10^23 / 0.0635

n = 8.49x10^28 atom/m³

Now with the value of n, we can finally calculate the time:

<em>t = nqAd / I </em>

A is the area and it should be in m²: 44.6 mm² / 1x10^6 m = 4.46x10^-5 m²

d is the length in meter: 75.7 cm / 100 cm/m = 0.757 m

so replacing these data in (5):

t = 8.49x10^28 * 1.6x10^-19 * 4.46x10^-5 * 0.757 / 137

t = 3,347.63 s

But the answer is in minute so:

t = 3,347.63 / 60

<em>t = 55.79 min</em>

so the electrons takes 56 min aprox. to go from the car battery to the starting motor.

You might be interested in
5. What happens to the mass when you change<br> the volume?<br> It decreases
anastassius [24]

Explanation:If the mass of the object stays the same but the volume of the object decreases then its density becomes greater. If the volume of the object stays the same but the mass of the object increases then its density becomes greater.

7 0
2 years ago
Gizmo Student Exploration: Periodic Trends awner key, Please I need help with this as soon as possible! I have attached what I h
Vlad [161]

Answer:

I cant see it

Explanation:

6 0
2 years ago
Which colligative property is employed when salt is put on an icy sidewalk to melt ice?
ankoles [38]
<span>The correct answer is 'freezing point depression'. Colligative properties depend on the concentration of molecules of a solute. Examples of other colligative properties are boiling point elevation or vapour pressure lowering. The salt causes ice on the side walk to melt because it lowers the freezing point. </span>
4 0
3 years ago
Read 2 more answers
A certain amount of hydrogen peroxide was dissolved in 100. mL of water and then titrated with 1.68 M KMnO4. What mass of H2O2 w
Stels [109]

Answer:

see explanation below

Explanation:

First to all, this is a redox reaction, and the reaction taking place is the following:

2KMnO4 + 3H2SO4 + 5H2O2 -----> 2MnSO4 + K2SO4 + 8H2O + 5O2

According to this reaction, we can see that the mole ratio between the peroxide and the permangante is 5:2. Therefore, if the titration required 21.3 mL to reach the equivalence point, then, the moles would be:

MhVh = MpVp

h would be the hydrogen peroxide, and p the permanganate.

But like it was stated before, the mole ratio is 5:2 so:

5MhVh = 2MpVp

Replacing moles:

5nh = 2MpVp

Now, we just have to replace the given data:

nh = 2MpVp/5

nh = 2 * 1.68 * 0.0213 / 5

nh = 0.0143 moles

Now to get the mass, we just need the molecular mass of the peroxide:

MM = 2*1 + 2*16 = 34 g/mol

Finally the mass:

m = 0.0143 * 34

m = 0.4862 g

8 0
3 years ago
What are 2 interactions between the earth spheres and the carbon cycle?
Fed [463]

Answer:

Explanation:

The spheres interact with each other, and a change in one area can cause a change in another. Humans (biosphere) use farm machinery manufactured from geosphere materials to plow the fields, and the atmosphere brings precipitation (hydrosphere) to water the plants. The biosphere contains all the planet's living things.

6 0
3 years ago
Other questions:
  • A (non-aqueous ) solution is found to have a molarity of 2.50 molal and experiences a freezing point depression of 5.20 degree C
    7·1 answer
  • Why is second ionization energy larger than first ionization energy
    9·2 answers
  • What element has an atomic number of 20 and two valence electrons in its valence shell?
    6·1 answer
  • What does water taste of? Don't say nothing everything has a taste!
    8·2 answers
  • What are the difference between a red giant and a red super giant
    15·2 answers
  • HELP PLS AND THANK U FAST PLS &lt;3
    8·1 answer
  • Looking at the web above, each letter represents a species of animal in an ecosystem food web. Which of the following is most li
    11·1 answer
  • How much energy is required to change the temperature of 35.0 g of Lead
    7·1 answer
  • Please please please someone give me the answers to all of these our teacher is very bad at explaining things and we are all con
    11·1 answer
  • Read, now please rail me jkjkjk.................Unless
    11·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!