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
7nadin3 [17]
3 years ago
15

Heat can be transferred through conduction, convection, and radiation. What is necessary in order for heat to be transferred by

conduction?
A.
Heat must be transferred through space.
B.
Heat must be transferred in the form of currents.
C.
The substances must be liquids or gases.
D.
The objects must be in direct contact with one another.
Physics
2 answers:
Pie3 years ago
7 0
Conduction is a mode of heat transfer where thermal energy flows between bodies that are in direct contact. Thus, the correct answer would be D.

A is incorrect here: heat flow via conduction involves high-energy particles (such as atoms or molecules) having their energy transferred to neighboring particles by contact or collision. If “space” refers to a region that contains only gas (the everyday understanding of “space”), then heat transfer by conduction would be extremely inefficient since gas molecules are so far apart. If “space” refers to a vacuum, then conduction cannot occur at all (radiation is the only mode of heat transfer through a vacuum). In either case, not only does conduction not necessitate space, but space impedes heat transfer by conduction.

B is incorrect because conduction operates via the movement of energy itself and not of matter (although, as we established above, the presence of matter is necessary for conduction). Conductive heat transfer can occur within a body itself (a metal bar that is heated on one end will eventually become hot on the other end). So, apart from being definitionally incorrect, conductive heat transfer doesn’t require currents at all. This mode of heat transfer occurs in convection.

C is manifestly incorrect: conductive heat transfer can occur between or within solids, so it can’t possibly be necessary that the “substances . . . Be liquids or gases.
jeka943 years ago
3 0

it would be..... C

sorry if I am wrong I tryed to think, At least I try!

You might be interested in
A pendulum with a length of 1 meter is released from an initial angle of 15.0° after 1000s its amplitude has been reduced by fri
Setler [38]

Answer:

0.366×10^{-3} / s

Explanation:

θ = θmax e^{-bt/2m}

Given that

             θ = 5.50°

             θmax = 15.0°

So that we have

                ln (θ / θmax) = -bt /2m

            = - ln(5.50°/ 15.0°) / 1000s = b /2m

             = b / 2m = 0.366×10^{-3} / s

3 0
3 years ago
A permeability test was run on a compacted sample of dirty sandy gravel. The sample was 175 mm long and the diameter of the mold
LUCKY_DIMON [66]

Answer:

(a). The coefficient of permeability is 8.6\times10^{-3}\ cm/s.

(b). The seepage velocity is 0.0330 cm/s.

(c). The discharge velocity during the test is 0.0187 cm/s.

Explanation:

Given that,

Length = 175 mm

Diameter = 175 mm

Time = 90 sec

Volume= 405 cm³

We need to calculate the discharge

Using formula of discharge

Q=\dfrac{V}{t}

Put the value into the formula

Q=\dfrac{405}{90}

Q=4.5\ cm^3/s

(a). We need to calculate the coefficient of permeability

Using formula of coefficient of permeability

Q=kiA

k=\dfrac{Q}{iA}

k=\dfrac{Ql}{Ah}

Where, Q=discharge

l = length

A = cross section area

h=constant head causing flow

Put the value into the formula

k=\dfrac{4.5\times175\times10^{-1}}{\dfrac{\pi(175\times10^{-1})^2}{4}\times38}

k=8.6\times10^{-3}\ cm/s

The coefficient of permeability is 8.6\times10^{-3}\ cm/s.

(c). We need to calculate the discharge velocity during the test

Using formula of discharge velocity

v=ki

v=\dfrac{kh}{l}

Put the value into the formula

v=\dfrac{8.6\times10^{-3}\times38}{17.5}

v=0.0187\ cm/s

The discharge velocity during the test is 0.0187 cm/s.

(b). We need to calculate the volume of solid in the ample

Using formula of volume

V_{s}=\dfrac{M_{s}}{V_{s}}

Put the value into the formula

V_{s}=\dfrac{4950\times10^{-3}}{2710}

V_{s}=1826.56\ cm^3

We need to calculate the volume of the soil specimen

Using formula of volume

V=A\times L

Put the value into the formula

V=\dfrac{\pi(17.5)^2}{4}\times17.5

V=4209.24\ cm^3

We need to calculate the volume of the voids

V_{v}=V-V_{s}

Put the value into the formula

V_{v}=4209.24-1826.56

V_{v}=2382.68\ cm^3

We need to calculate the seepage velocity

Using formula of velocity

Av=A_{v}v_{s}

v_{s}=\dfrac{Av}{A_{v}}

v_{s}=\dfrac{V}{V_{v}}\times v

Put the value into the formula

v_{s}=\dfrac{4209.24}{2382.68}\times0.0187

v_{s}=0.0330\ cm/s

The seepage velocity is 0.0330 cm/s.

Hence, (a). The coefficient of permeability is 8.6\times10^{-3}\ cm/s.

(b). The seepage velocity is 0.0330 cm/s.

(c). The discharge velocity during the test is 0.0187 cm/s.

8 0
3 years ago
A bicycle travels 141 m along a circular track of radius 30 m. What is the angular displacement in radians of the bicycle from i
Veseljchak [2.6K]

Answer: 4.7rad

Explanation:

Angular displacement =s/r

Where s=distance traveled

r=radius

Angular displacement =141m/30m

Angular displacement =4.7rad.

5 0
3 years ago
Points A, B, and C lie along a line from left to right, respectively. Point B is at a lower electric potential than point A. Poi
djyliett [7]

Answer:

A) The particle will accelerate in the direction of point C.

Explanation:

As we know that

potential at points A, B,C and D as V_A, V_B, V_C, V_D  and it is clear from the question that

V_A>V_B>V_C

And we know that flow is always from higher to lower potential (for positive charge due to positive potential energy).

So the charge will accelerate from B toward C.

Hence, the correct option is A.

6 0
3 years ago
A car's gas tank contains 58.7 kg
Bogdan [553]

Answer:

721 kg/m^3

Explanation:

Trust me bro

8 0
3 years ago
Other questions:
  • 1.When I cook an egg in a microwave oven, the device uses electromagnetic energy to increase the kinetic energy of particles of
    9·1 answer
  • 3.Cuanto Calor pierden 514 ml de agua si su temperatura desciende de 12°C a 11°C. Expresa el resultado en calorias.
    11·1 answer
  • A lamp has a current of 2.17 A. In hours, how long does it take for 1 mole of electrons to pass through the lamp?
    5·1 answer
  • Model the concrete slab as being surrounded on both sides (contact area 24 m2) with a 2.1-m-thick layer of air in contact with a
    14·1 answer
  • The number of oscillations that a wave completes per unit of time in called its _______.
    13·1 answer
  • Which of the following describes work?
    5·2 answers
  • The ________ is located inside the outdoor condenser unit and receives the low-pressure refrigerant vapor through the suction li
    8·1 answer
  • A toy cannon tosses a rubber ball straight upward. A motion sensor measures the speed of the ball as it leaves the cannon. Using
    11·1 answer
  • You compress a spring by x, and then release it. Next you compress the spring by 2x. How much more work did you do the second ti
    5·1 answer
  • Identify the amplitude of the wave using the picture below.
    6·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!