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3 years ago

Convection only occurs in what? a. gases b. fluids c. liquids d. solids

Physics

2 answers:

Butoxors [25]3 years ago

7 0

the answer on edginuity is B- Fluids (i just took the test)

vekshin13 years ago

3 0

Answer:

b. Fluids

Explanation:

Convection is one of the three methods of transfer of heat. Let's define them all:

- Conduction: conduction occurs when two objects (or two substances) are in contact with each other; heat is transferred from the warmer object to the colder object by the collisions between the particles of the warmer object (which have on average greater kinetic energy) and the particles of the colder object (which have on average smaller kinetic energy). This type of heat transfer can occur in solids, liquids and gases.

- Convection: convection occurs when there is a fluid which is heated from a heat source. As the part of the fluid closer to the heat source becomes warmer, it becomes less dense and it expands, rising and being replaced by the part of the fluid which is colder. Then, the mechanism continues, generating a convection current (like a cycle) which transport the heat over the whole fluid. This method of heat transfer occurs in fluids (liquids and gases) only.

- Radiation: radiation occurs when heat is carried by electromagnetic waves (which transport energy, so also heat, through space). Radiation can occur in any medium, and can also occur in vacuum since electromagnetic waves can travel in vacuum as well.

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A CD-ROM drive in a computer spins the 12-cm-diameter disks at 9500 rpm. Find acceleration in units of g that a speck of dust on

NeTakaya

The net force on an object is:
F = ma
The only force acting on the speck of dust as it is lays on the CD is centripetal force given by:
F = (mv²)/r
Equating the two
ma = (mv²)/r
We get:
a = v²/r
v is the linear velocity in this case; however, we can calculate only the angular velocity with the given data. Therefore, we must use:
v = ωr; where
ω = 2πf; f is the rotations per second
f = 9500 / 60
f = 950/6
ω = 2π(950/6)
ω = (950π)/3
v = (950π)/3 × 0.12
v = 38π
a = (38π)²/0.12
a = 1.2 × 10⁵ m/s²
To express this in terms of gravitational acceleration, we divide by the value of gravitational acceleration, 9.81
a = 1.2 × 10⁴ g

4 0

3 years ago

HELP!!!

abruzzese [7]

17.7m/s

Explanation:

Given parameters:

Height of branch = 16m

Unknown:

Velocity before falling = ?

Solution:

We are going to use the appropriate motion equation to solve this problem.

The bird is falling in line with the action of gravity.

Initial velocity is 0 for the bird.

Let the velocity during flight = V;

Then;

V² = U² + 2gH

since U = 0

V² = 2gH

V is the unknown velocity

H is the height of fall

g is the acceleration due to gravity

V = √2gH = √ 2x9.8 x 16 = 17.7m/s

learn more:

Velocity brainly.com/question/4460262

#learnwithBrainly

6 0

3 years ago

QC Suppose you hear a clap of thunder 16.2s after seeing the associated lightning strike. The speed of light in air is 3.00× 10⁸

MAVERICK [17]

If you hear a clap of thunder in a time of 16.2s after seeing the associated lightning strike, you are: 5508 m far from the lightning strike

To solve this problem we must consider that the speed of light is greater than the speed of sound, therefore to calculate the distance we must use the speed of sound (340 m/s).

The formula and procedure we will use to solve this exercise is:

x = v * t

Where:

x = distance
t = time
v = velocity

Information about the problem:

v(sound) = 340 m/s
t = 16.2 s
x=?

Applying the distance formula we have that:

x = v * t

x= 340 m/s * 16.2 s

x = 5508 m

<h3>What is velocity?</h3>

It is a physical quantity that indicates the displacement of a mobile per unit of time, it is expressed in units of distance per time, for example (miles/h, km/h).

Learn more about velocity at: brainly.com/question/80295?source=archive

#SPJ4

7 0

1 year ago

What is the speed of sound in solid? <br>

sasho [114]

The speed of sound in a solid would be 6000 metres per second

7 0

2 years ago

Read 2 more answers

You are given two vectors vector A = 4.9 at 31o vector B = 6 at 156o Angles are measured counterclockwise from the x-axis. What

Ket [755]

Answer:

C_{y} = 4.96 and θ' = 104,5º

Explanation:

To add several vectors we can decompose each one of them, perform the sum on each axis, to find the components of the resultant and then find the module and direction.

Let's start by decomposing the two vectors.

Vector A

sin θ = $A_{y}$ / A

cos θ = Aₓ / A

A_{y} = A sin θ

Ax = A cos θ

A_{y} = 4.9 sin 31 = 2.52

Ax = 4.9 cos 31 = 4.20

Vector B

B_{y} = B sin θ

Bx = B cos θ

B_{y} = 6 sin 156 = 2.44

Bx = 6 cos 156 = -5.48

The components of the resulting vector are

X axis

Cx = Ax + B x

Cx = 4.20 -5.48

Cx = -1.28

Axis y

C_{y} = Ay + By

C_{y} = 2.52 + 2.44

C_{y} = 4.96

Let's use the Pythagorean theorem to find modulo

C = √ (Cₙ²x2 + Cy2)

C = Ra (1.28 2 + 4.96 2)

C = 5.12

We use trigonemetry to find the angle

tan θ = C_{y} / Cₓ

θ’ = tan⁻¹ (4.96 / (1.28))

θ’ = 75.5

como el valor de Cy es positivo y Cx es negativo el angulo este en el segundo cuadrante, por lo cual el angulo medido respecto de eje x positivo es

θ’ = 180 – tes

θ‘= 180 – 75,5

θ' = 104,5º

7 0

3 years ago