Does the coefficient of kinetic friction depend on the speed?

Answer:

The anomalous expansion of water is an abnormal property of water whereby it expands instead of contracting when the temperature goes from 4o C to 0o C, and it becomes less dense. The density is maximum at 4 degree centigrade and decreases below that temperature as shown in graph.

Explanation:do you want me to explain it more??

The water behind a hydroelectric dam stores gravitational potential energy since it is at a higher level than the water on the other side of the dam. As the water falls, this potential energy is converted into kinetic energy, which turns turbines to generate electricity. Often, the water comes from behind a dam built across a river valley. The water high up behind the dam contains gravitational potential energy . This is transferred to kinetic energy as the water rushes down through tubes inside the dam. The moving water drives electrical generators , which may be built inside the dam.

[tex]I = \frac{V}{R} \\ [/tex]

Thus :

[tex]I = \frac{160}{2} \\ [/tex]

[tex]I = 80 \: \: A[/tex]

So :

[tex]V = 160[/tex]

[tex]I = 80[/tex]

[tex]R = 2[/tex]

Answer:

Mechanical Sound Waves - A sound wave moves through air by displacing air particles in a chain reaction. ... Sound energy, or energy associated with the vibrations created by a vibrating source, requires a medium to travel, which makes sound energy a mechanical wave. For pitch the higher the frequency, the higher the pitch. Frequency is measured in hertz, or cycles per second. Frequency also affects loudness, with higher-pitched sounds being perceived as louder. Amplitude and frequency of sound waves interact to produce the experiences of loudness and pitch.

Considering the change of units and the definition of weight, the mass of two washers would be 0.0098 kg and if 4 washers are attached to the string, then the applied force on the car will be 0.196 N.

If each washer has a mass of 4.9 g, then the mass of two washers will be calculated simply by multiplying the mass of 1 washer by the amount you have of them, in this case 2:

4.9 g×2= 9.8 g

Being 1 kg = 1000 g, you apply the following rule of three to make the change of units: if 1000 g equals 1 kg, 9.8 g equals how many kilograms?

[tex]mass=\frac{9.8 gramsx1 kg}{1000g}[/tex]

Solving:

mass= 0.0098 kg

Finally, the mass of two washers would be 0.0098 kg.

On the other side, mass is the amount of matter that a body contains and weight is the action exerted by the force of gravity on the body.

The mass of an object will always be the same, no matter where it is located. Instead, the weight of the object will vary according to the force of gravity acting on it.

Weight is calculated as the product of the object's mass and the value of the gravitational acceleration:

W= m×g

In this case, you know:  

Replacing:

W= 0.0196 kg× 10 m/s²

Solving:

W= 0.196 N

Finally, if 4 washers are attached to the string, then the applied force on the car will be 0.196 N.

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Answer:

C, B

Explanation:

The mass of the satellite will remain the same when it is accelerated away from the Earth.

The mass of an object is a scalar quantity. This implies that mass of an object can be completely described with magnitude only.

The mass of every object in the universe is independent of the gravity and will always maintain the same value from place to place.

Thus, we can conclude that, the mass of the satellite will remain the same when it is accelerated away from the Earth.

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For this case, the relationship between the two forces is given by:

F1 = nF2

Where,

Then, replacing the values we have:

F1 = (2.2)(202)

Having the calculations we have:

F1 = 444.4N

Answer: The output force that only lifts the load is F1 = 444.4N.

Answer:

Answer 3: When a balloon goes up higher in the air, its size will increase. Since there's less air in the upper atmosphere, there's less stuff pushing back on the balloon, and hence the pressure is lower, which allows the balloon to expand

Answer: C

Explanation:

As the balloon rises, the gas inside the balloon expands because the atmospheric pressure surrounding the balloon drops. The atmosphere is 100 to 200 times less dense at the float altitudes than on the ground. and as the air is heated inside the balloon it causes it to rise upwards (because it is lighter than the cooler air on the outside). When the pilot needs to bring the balloon down again, he simply reduces the temperature of the air inside the balloon causing it to slowly descend.

Energy is transformed and transferred in a thermodynamic system. Option B is correct

First law of thermodynamics:

It states the energy neither be created nor destroyed. It change its form from one to another. It is also known as law of conservation of energy.

It is given by the formula,

[tex]\Delta U = Q - W[/tex]

Where,

[tex]\Delta U[/tex] - change in internal energy

[tex]Q[/tex] -    heat added

[tex]W[/tex]-    work done by the system

Since, heat is a form of energy, hence it is follow the principle of conservation of energy.

Therefore, energy is transformed and transferred in a thermodynamic system. Option B is correct

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Answer:

2: A,D,E or 1,4,5

3: B

4: B

5: 12 joules

6: 53 joules

7: B,C,E or 2,3,5

8: 2,4,3,1

9: Electrical energy in the stove is transformed into heat. The heat flows to the water in the kettle, increasing the internal energy of the water. As the energy in the water increases, the water molecules move faster until the liquid water becomes water vapor. The water vapor does work on the whistle, causing it to make a sound. Energy is neither created nor destroyed, it has simply changed form in the process.

Explanation:

youre welcome

Explanation:

yayyy thx u soo muchihuhuhu

Answer:

thx

Explanation:

Answer:

electricity because it has more percentage nd energy

Explanation:

mark me brainliest pl

Answer:

F = G M m / R^2 = 6.67E-11 * 1.99E30 * 5.98E24 / (1.5E11)^2

F = 6.67 * 1.99 * 5.98 / 2.25 E21 Newtons

F = 3.53E22 N

Answer:

thats ummm

Explanation:

law of inertia

Newton’s 1 law

Answer:

Yes, they do. When two different materials are rubbed together, there is a transfer of electrons from one material to the other material. This causes one object to become positively charged and the other object to become negatively charged.

Explanation:

hope this helps

Answer:

  C

Explanation:

Most discussions of refraction will have a diagram similar to that of C.

The angle of incidence is measured from the normal to the boundary, as is the angle of refraction. The product of the sine of the angle and the index of refraction is the same for the media on either side of the boundary.

  n₁·sin(θ₁) = n₂·sin(θ₂)

For media, such as optical fiber, that has an index of refraction greater than 1, the angle of refraction will be smaller in that media than the angle of incidence coming from air.

Figure C applies.

Answer:

4 m/s^2

Explanation:

The acceleration is defined as: Δv/Δt (the difference of the velocity over a time period in which happens that difference).

Remember that a difference is calculated by subtracting the initial value of a physical quantity from its final value.

In our case:

Δv = Vfinal - Vinitial = 36m/s - 0 m/s = 36m/s

Δt = 9s

a = Δv/Δt = 36m/s / 9s = 4m/s^2

Answer:

refraction

Explanation:

but this is easy so why

Since every ice crystal takes a different route to the ground. They will float through various clouds with various temperatures and moisture contents, which will cause the ice crystal to develop in a distinctive manner.

A snowflake's shape changes as it flies through the atmosphere, thus no two are ever the same. Even two flakes floating side by side will each be blown through various vapour and humidity levels to produce a genuinely unique shape.

One of the most recognizable representations of winter weather are snowflakes. There are an unlimited amount of conceivable shapes for snowflakes, and each one is distinct.

Therefore, snowflakes unique even though there are billions.Even two floating flakes will each be exposed to different vapour and humidity conditions, creating a really distinctive form.

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#SPJ2

Explanation:

Final velocity=Initial velocity+(acceleration×time)

4 ways to find initial velocity:

1) Initial velocity=Final velocity-(acceleration×time)

2) Initial velocity=(Distance/Time)-((acceleration×time)/2)

3) Initial velocity=√Final velocity-(2×(acceleration×distance))

4) Initial velocity=2(distance/time)-Final velocity

Total force = Mass×Acceleration

(F=ma)

Answer:

he expected a fire to happen I think

Answer:

When Ernest Rutherford aimed a beam of particles at a thin gold foil he expected that the particles would be deflected slightly after passing through the foil.

Explanation:

hope it helped

This question involves the concepts of the law of conservation of energy and kinetic energy.

The girl's fastest speed is "3.7 m/s".

According to the law of conservation of energy, the girl will have the fastest speed at mean position, which will be calculated as follows:

Loss in Potential Energy = Gain in Kinetic Energy

[tex]mg\Delta h=\frac{1}{2}mv^2\\\\v=\sqrt{2g\Delta h}[/tex]

where,

v = maximum speed = ?

g = acceleration due to gravity = 9.81 m/s²

Δh = change in height = 1.3 m - 0.6 m = 0.7 m

Therefore,

[tex]v=\sqrt{2(9.81\ m/s^2)(0.7\ m)}[/tex]

v = 3.7 m/s

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Answer:

[tex]\\ \tt\hookrightarrow \dfrac{(3\times 10^4kg)(4\times 10^4m)}{6\times 10^4s)}[/tex]

[tex]\\ \tt\hookrightarrow \dfrac{12\times 10^8kgm}{6\times 10^4s}[/tex]

[tex]\\ \tt\hookrightarrow 2kgm/s[/tex]

We have calculated momentum

Destruction of property from lava flow, destruction from mud flows and lung problems from ash and toxic gases are all some of the dangers that volcanoes pose to human populations.

Volcanoes refer to an opening that appears on the earth's surface and serves as a vent for lava, volcanic ash, and gases. These could lead to a fire outbreak in mountains sometimes.

The following are dangers posed by volcanoes pose to human populations;

Hence, the correct answer to the question is "all of the above".

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Answer:

D

Explanation:

EDGE 2021

331.29 metres (1,086.9 feet) per

Answer:

The answer is true I guess!!!

This is because the more you go up to less air it is and the pressure also gets less!!!!!!!!

Explanation:

I HOPE THAT I WAS HELPFUL TO YOU!