What happens to the temperature of a substance while it is changing state?
A. It increases first and then decreases.
B. It decreases first and then remains constant.
C. It varies randomly.
D. It remains constant.

Answer: Option B.

Explanation:

I guess that this refers to the Badminton rules, particularly to the position of the racket (or the head of the racket, where the "head" is the part with the net, that you use to hit the shuttle) when serving.

The head of the racket must be swung from below your waist. So the head of the racket must be below your waist before you do the service (With a part of the head is enough).

Then the correct option is B. Below the waist.

Answer:

The correct option is;

c. 12.8 cm

Explanation:

The given parameters are;

The length of each spring = 12 m  = 0.12 m

Given that the masses and the springs are vertically oriented, we have;

The mass on the first spring = 3 × 6.4 = 19.2 kg

The weight on the first spring = 19.2 kg × 9.81 m/s² = 188.352 N

The extension of the first spring = 188.352 N/7,800 N/m ≈ 0.02415 m

The mass on the second spring = 2 × 6.4 = 12.8 kg

The weight on the second spring = 12.8 kg × 9.81 m/s² = 125.568 N

The extension of the second spring = 125.568 N/7,800 N/m ≈ 0.016098 m

The mass on the third spring = 1 × 6.4 = 6.4 kg

The weight on the third spring = 6.4 kg × 9.81 m/s² = 62.784 N

The extension of the third (bottom) spring = 62.784 N/7,800 N/m ≈ 0.00805 m

The total length of the bottom spring = Original length of the bottom spring + Extension of the bottom spring

The total length of the bottom spring ≈ 0.12 m + 0.00805 m = 0.12805 m

The total length of the bottom spring ≈ 0.12805 m ≈ 12.81 cm

The bottom spring will be approximately 12.81 cm long.

Answer:

Momentum is directly proportional to the object's mass and also its velocity. Thus the greater an object's mass or the greater its velocity, the greater its momentum. Momentum p is a vector having the same direction as the velocity v. The SI unit for momentum is kg · m/s.

Answer:

Momentum is directly proportional to the object's mass and also its velocity. Thus the greater an object's mass or the greater its velocity, the greater its momentum. Momentum p is a vector having the same direction as the velocity v. The SI unit for momentum is kg · m/s.

Explanation:

Answer:

a. 0.122 ft b. -70 Btu/h ft² c. 633.33 °F

Explanation:

a. Since the rate of heat loss dQ/dt = kAΔT/d where k = thermal conductivity, A = area, ΔT = temperature gradient and d = thickness of insulation.

Now [dQ/dt]/A = kΔT/d

Given that [dQ/dt]/A = rate of heat loss per unit area = -900Btu/h ft², k = 0.10 Btu/h ft ℉(for asbestos), ΔT = T₂ - T₁ = 500 °F - 1600 °F = -1100 °F. We need to find the thickness of asbestos, d. So,

d = kΔT/[dQ/dt]/A

d = 0.10 Btu/h ft ℉ × -1100 °F/-900Btu/h ft²

d = 0.122 ft

b. If the 3 in thick Kaolin is added to the outside of the asbestos, and the outside temperature of the asbestos is 250℉, the heat loss due to the Kaolin is thus

[dQ/dt]/A = k'ΔT'/d'

k' = 0.07 Btu/h ft ℉(for Kaolin), ΔT' = T₂ - T₁ = 250 °F - 500 °F = -250 °F and d' = 3 in = 3/12 ft = 0.25 ft

[dQ/dt]/A = 0.07 Btu/h ft ℉ × -250 °F/0.25 ft

[dQ/dt]/A  = -70 Btu/h ft²

c. To find the temperature at the interface, the total heat flux equals the individual heat loss from the asbestos and kaolin. So

[dQ/dt]/A = k(T₂ - T₁)/d + k'(T₃ - T₂)/d' where  [dQ/dt]/A = -900Btu/h ft², k = 0.10 Btu/h ft ℉(for asbestos), k' = 0.07 Btu/h ft ℉(for Kaolin), T₁ = 1600 °F, T₂ = unknown and T₃ = 250℉.

Substituting these values into the equation, we have

-900Btu/h ft² = 0.10 Btu/h ft ℉(T₂ - 1600 °F)/0.122 ft + 0.07 Btu/h ft ℉(250℉ - T₂)/0.25 ft

-900Btu/h ft² = 0.82 Btu/h ft ℉(T₂ - 1600 °F) + 0.28Btu/h ft ℉(250℉ - T₂)

-900 °F = 0.82(T₂ - 1600 °F) + 0.28(250℉ - T₂)

-900 °F = 0.82T₂  - 1312°F + 70 °F - 0.28T₂

collecting like terms, we have

-900 °F + 1312°F - 70 °F = 0.82T₂   - 0.28T₂

342 °F = 0.54T₂

Dividing both sides by 0.54, we have

T₂ = 342 °F/0.54

T₂ = 633.33 °F

The thickness of asbestos required is 0.122 ft.

The heat flux will be -70 Btu/h ft²

And the temperature of the interface is 633.33 °F.  

(i) the rate of heat loss :

dQ/dt = kAΔT/d

where k = thermal conductivity, A = area, ΔT = temperature gradient, and

d = thickness of insulation.

[dQ/dt]/A = kΔT/d

Given that [dQ/dt]/A = rate of heat loss per unit area = -900Btu/h ft²,

k = 0.10 Btu/h ft ℉,

ΔT = 500 °F - 1600 °F = -1100 °F

We have to find the thickness of asbestos that is d.

d = kΔT/[dQ/dt]/A

d = 0.10 Btu/h ft ℉ × -1100 °F/-900Btu/h ft²

d = 0.122 ft is the thickness required.

(ii) a 3-in thick Kaolin is added to the outside of the asbestos

outside temperature of the asbestos is 250℉,

the heat loss due to the Kaolin is:

[dQ/dt]/A = k'ΔT'/d'

k' = 0.07 Btu/h ft ℉(for Kaolin), ΔT' = T₂ - T₁ = 250 °F - 500 °F = -250 °F and d' = 3 in = 3/12 ft = 0.25 ft

[dQ/dt]/A = 0.07 Btu/h ft ℉ × -250 °F/0.25 ft

[dQ/dt]/A  = -70 Btu/h ft²

(iii) temperature at the interface

the total heat flux :

[dQ/dt]/A = k(T₂ - T₁)/d + k'(T₃ - T₂)/d'

where  [dQ/dt]/A = -900 Btu/h ft²,

k = 0.10 Btu/h ft ℉  (for asbestos),

k' = 0.07 Btu/h ft ℉  (for Kaolin),

T₁ = 1600 °F and T₃ = 250℉.

-900 = 0.10(T₂ - 1600 °F)/0.122 + 0.07(250℉ - T₂)/0.25

-900 = 0.82(T₂ - 1600 °F) + 0.28(250℉ - T₂)

-900 °F = 0.82(T₂ - 1600 °F) + 0.28(250℉ - T₂)

-900 °F = 0.82T₂  - 1312°F + 70 °F - 0.28T₂

-900 °F + 1312°F - 70 °F = 0.82T₂   - 0.28T₂

342 °F = 0.54T₂

Dividing both sides by 0.54, we have

T₂ = 342 °F/0.54

T₂ = 633.33 °F

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Answer:  are u single

Explanation:

Answer:

Hope this answered your question!~ (Sorry if you get it wrong or I got it wrong-)

Explanation:

When an impact event happens, the enormous kinetic energy of the asteroid or meteorite – a massive body travelling at high speed – is partly transferred to the Earth but largely converted into heat and sound, creating pressure waves travelling radially outwards from its centre, similar to that of an atom bomb.

~The Confuzzeled homan

Answer:

All 7 Dragonballs

Explanation:

the dragonball Summon shenron which will then grant you a wish

Answer:

I think it is 2m/s2

Explanation:

Have a great day:)

Answer:

The vacuum of outer space is not caused by the expansion of the universe, but is caused by gravity.

Explanation:

Answer:

The object starts away from the origin and then moves toward the origin at a constant velocity. Next, it stops for one second. Finally, it moves away from the origin at a greater constant velocity.

Explanation:

Sample Response: The object starts away from the origin and then moves toward the origin at a constant velocity. Next, it stops for one second. Finally, it moves away from the origin at a greater constant velocity.

What did you include in your description? Check all that apply.

The object starts away from the origin.

The object moves toward the origin at a constant velocity.

The object stops for one second.

The object moves away from the origin at a greater constant velocity.

The circled vectors represent speed.

The is the ratio of distance traveled to time of motion. Speed is a scalar quantity because it has only only magnitude.

From the map, as the magnitude (size) of the green arrows changes, the size of the circled arrows changes accordingly.

Also, the direction of the circled arrow was constant for both top and bottom arrows.

Velocity changes with direction BUT speed does not change with direction, and has a complete meaning with only magnitude.

Thus, the circled vectors represent speed.

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Answer:

Answer:Lead by an example

Practice what you preach. You'll never convince anyone to conserve water if you aren't doing it yourself.

Engage with others.

Seek out allies.

Give people a reason to save.

Provide entry-level strategies.

Encourage others to challenge themselves.

Think big.

Choose a monthly focus.

Answer:

m2 = 13950 [kg]

Explanation:

To solve this problem we must use the principle of conservation of linear momentum, which is defined as the product of mass by velocity, and can be determined by means of the following expression:

P = m*v

where:

P = lineal momentum [kg*m/s]

m = mass [kg]

v = velocity [m/s]

Now that momentum is conserved, we need to analyze the conditions before the collision and after the collision. In this way we must propose the following equation:

ΣPbefore = ΣPafter

(m1*v1) + (m2*v2) = (m1+m2)*v3

where:

m1 = mass of the railroad car = 9300 [kg]

v1 = velocity of the railroad car before the collision = 15 [m/s]

m2 = mass of the box car [kg]

v2 = velocity of the boxcar before the collision = 0 (the car is at rest)

(m1 + m2) = combined mass of the cars, they stick together after the collision [kg]

v3 = combined velocity of the cars after the collision = 6 [m/s]

(9300*15) + (m2*0) = (m1+m2)*6

139500 = (6*9300) + 6*m2

83700 = 6*m2

m2 = 13950 [kg]

The mass of the second railroad car which was initially at rest is 13950kg.

Given the data in the question;

Mass of railroad car2; [tex]m_2 = \ ?[/tex]

Since railroad car2 was initially at rest,

After the strike, the wo cars stick together and moved

To determine the mass of the second railroad car, we use conservation of linear momentum:

[tex]m_1u_1 + m_2u_2 = (m_1 + m_2 )v[/tex]

We substitute our given values into the equation

[tex](9300kg * 15m/s) + ( m_2 * 0 ) = ( 9300kg + m_2 )6m/s\\\\9300kg * 15m/s = ( 9300kg + m_2 )6m/s\\\\139500kg.m/s = 55800kg.m/s + ( m_2 * 6m/s )\\\\139500kg.m/s - 55800kg.m/s = m_2 * 6m/s\\\\83700kg.m/s = m_2 * 6m/s\\\\m_2 = \frac{83700kg.m/s}{6m/s} \\\\m_2 = 13950kg[/tex]

Therefore, the mass of the second railroad car which was initially at rest is 13950kg.

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Answer:

the innermost layer of the earth

Explanation:

the earth has an outer core liquid and an inner core solid they are not chemically distinct from each other but they are chemically distinct from the mantle the core is mainly composed of nickel and iron

Answer:

I don't know how to show the work but I just had this question and the answer is 9.24kg.

Explanation:

Answer:

4200 Newtons

Explanation:

Force = mass x acceleration

1200 x 3.5 = 4200

¡Hellow!

For this problem, first, lets convert the seconds in hours:

5,4x10³[tex]\rightarrow[/tex] 5400

h = sec / 3600

h = 5400 s / 3600

h = 1,5

Let's recabe information:

d (Distance) = 386 km

t (Time) = 1,5 h

v (Velocity) = ?

For calculate velocity, let's applicate formula:

                                                    [tex]\boxed{\boxed{\textbf{d = v * t} } }[/tex]

Reeplace according we information:

386 km = v * 1,5 h

v = 386 km / 1,5 h

v = 257,33 km/h

The velocity of the train is of 257,33 kilometers for hour.

Extra:

For convert km/h to m/s, we divide the velocity of km/h for 3,6:

m/s = km/h / 3,6

Let's reeplace:

m/s = 257,33 km/h / 3,6

m/s = 71,48

¿Good Luck?

Answer:

20 m

Explanation:

by the formula,

                         [tex]2aS = V_{f}^{2} - V_{i}^2[/tex]

                         2 x 10 x S = 20^2 - 0

                         20S = 400

                         [tex]S = \frac{400}{20}[/tex]

                          S = 20 m  

Answer:

about 16 hours

Explanation:

if driving 55mph for 16 hrs you will travel about 880 miles

Answer:

velocity = 2m/s

using v=fΠ

convert 100 CM to m

Answer:

200 cm per second

Explanation:

The equation for wave velocity=wavelength x frequency, since the wavelength is 100 and the frequency is two, the equation would be 100 x 2, which equals 200. Therefore, the correct answer is 200 cm per second.

Answer:

a chemical property can be observed without changing the identity of the substance.

Explanation:

a physical property is a characteristic that can be observed without changing the substance into another substance. The object reacts with acid to form water.

The only option that does not represent the relationship between culture and one's moral reasoning is one's thought and beliefs are generally independent of cultural influences.

Culture can be defined as the people's way of life. It is an umbrella term which encompasses the social behavior and norms found in human societies.

Moral reasoning is the process by which people apply their thought or make judgment in analyzing issues and making decisions.

Thus, the only option that does not represent the relationship between culture and one's moral reasoning is one's thought and beliefs are generally independent of cultural influences.

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Answer:

presence or absence of wind

Explanation:

When establishing a relationship between two variables the effect one variable has on the other is studied. The variable that changes with respect to the other is the dependent variable while the other variable is called the independent variable.

Here the distance the football covers in the presence and absence of wind is studied. So, the presence or absence of wind is the independent variable.

The answers is 30 miles per hour, the driver is speeding the car up,     section-H, 12 minutes, section-D, and 65 miles per hour.