please tell its urgent​

Answer:

Decrease

Explanation:

The pressure is the force per unit area. So, P=F/A

Thus the pressure P is inversely proportional to contact area A.

So when area increases , the pressure will be decreasing.

Answer:

Pascal is a derived unit because it cannot be expressed in any physics terms, but it is an expression of fundamental quantities.

Explanation:

[tex]{ \sf{Pasacal \: ( Pa) = \frac{newtons}{metres {}^{2} } }} \\ \\ { \sf{Pasacal \: (Pa) = \frac{kg \times {ms}^{ - 2} }{ {m}^{2} } }}[/tex]

Answer:

Explanation:

There is no pressure of your feet on the scales, and no pressure of the floor on the scales, so the scales will read zero*. Hence, your weight, in a freely falling lift is zero

Answer:

hi

Explanation:

pls mark as a BRAINLIST

Answer:

Elements in the same group have the same number of valence electrons.

When moving right across a period, the valence electrons of the main group elements increase by one.

When moving down a group, the valence electrons of the main group elements increase by one.

Elements in the same period have the same number of valence electrons.

Elements in the same period of the periodic table have valence electrons in the same energy levels.

When elements are in the same period on the periodic table, it means that they have the same number of shells.

The energy level of valence electrons in a atom depends on how far it is from the nucleus. This means that:

For instance, Boron, Carbon and Nitrogen will have valence electrons in the same energy levels.

In conclusion, elements in the same period will have valence electrons in the same energy levels.

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Answer:

any person who opens the door he applies pulling force

Answer:

True

Explanation:

The bigger an object is, the more force you must apply to move the object. Think about it like moving a mouse compared to moving an elephant. You can't move the elephant by yourself, because you don't have enough strength or force to move it. But, you can easily pick up a mouse, because it requires less force, or strength. Hope this helped :)

Answer:

I don't know

Explanation:

sorry but I will help u next time kk

Longitudinal waves

Transverse waves

Electromagnetic Waves

Water waves

Rope waves

LIght Waves

Explanation:

string roller is called an example of wheel and axel because The thin rod which needs to be turned is called the axle and the wider object fixed to the axle, on which we apply force is called the wheel.

hence the we apply force on the roller and the string gets tight.

my views

Explanation:

Figure (8) shows a rod made up of copper and wood joined together. The rod is heated at the joint in the centre for about a minute. At which point – A, B, C or D, would it show the lowest temperature? PLEASE GIVE REASONS ALSO(MINIMUM 2)

Answer:

Wait until the end of the semester to complete all work.

Explanation:

this is the obvious answer.

please mark me brainliest

Answer:

Wait until the end of the semester to complete all work

Answer:

The separation between the two stones is 36 m, when the second stone is approximately 10.9 m below the top of the cliff

Explanation:

The given parameters are;

The height of the cliff from which the stones are dropped, h = 60 m

The time at which the second stone is dropped = 1.6 seconds after the first

The distance below the top of the cliff when the distance between the two stones is 36 m = Required

We have;

The kinematic equation of motion that can be used is s = u·t - (1/2)·g·t²

For the first stone, we have, s₁ = u·t₁ - (1/2)·g·t₁²

For the second stone, we get; s₂ = u·t₂ - (1/2)·g·t₂²

t₁ = t₂ + 1.6

g = The acceleration due to gravity ≈ 9.81 m/s²

s = The distance below the cliff top

The initial velocity of the stones, u = 0

Let t represent the time from which the second stone is dropped at which the distance between the two stones is 36 m, we have;

s₁ = u·(t + 1.6) + (1/2)·g·(t + 1.6)²

s₂ = u·t + (1/2)·g·t²

u = 0

∴ s₁ - s₂ = 36 =  (1/2)·g·(t + 1.6)² - (1/2)·g·t²

2 × 36/(g) = (t + 1.6)² - t²  = t² + 3.2·t + 2.56 - t² = 3.2·t + 2.56

2 × 36/(9.81) = 3.2·t + 2.56

t = (2 × 36/(9.81) - 2.56)/3.2 =  ≈ 1.49 s

t ≈ 1.49 s

s₂ = (1/2)·g·t²

∴ s₂ = (1/2) × 9.81 × 1.49² ≈ 10.9

The distance below the top of the cliff of the second stone when the the separation between the two stones is 36 m, s₂ ≈ 10.9 m.

Answer:

Explanation:

We first need to convert the 40 km/h to m/s. Going by the fact that 40 has only 1 significant figure in it, 40 km/h = 10 m/s. The rest of the values are in their proper labels. We will use the equation:

[tex]v^2=v_0^2+2a[/tex]Δx where the final velocity is 0 because the car is coming to a stop at the end; the initial velocity is 10 m/s, the acceleration (or, rather, deceleration) is -.5 m/s/s, and our unknown which is displacement. Filling in:

[tex]0=(10)^2+2(-.5)[/tex]Δx and solving for Δx:

Δx = [tex]\frac{-100}{2(-.5)}[/tex] which ends up being simply that

Δx = 100 m

The hydro power plant consists of a (artificial) dam that builds gravitational potential energy, P.E. from natural flowing water sources, by locating the dam along the water path. The stored potential energy, P. is converted into kinetic energy, K.E. as the water falls from the dam, down to the turbines, located at a much lower level according to the following principle of conservation of energy equation;

Total Mechanical Energy, M.E. = The potential energy of the water, P.E. + The kinetic energy of the water, K.E. = Constant

M.E. = P.E. + K.E. = Constant

Where;

P.E. = m·g·h

K.E. = (1/2)·m·v²

m = Mass

g = The acceleration due to gravity

h = The height of the dam

v = The velocity

The charts can be explained as follows;

Given that the potential energy P.E. = m·g·h, we have that the potential energy is directly proportional to the height of the dam, and therefore, at mid height, the potential energy would be half the maximum value, and we have;

At mid height, P.E. = (1/2)·[tex]\mathbf{P.E._{max}}[/tex]

At the top of the dam, the (vertical) velocity of the water = 0, therefore, the kinetic energy = 0

Therefore, at the top of the dam, we get;

M.E. = [tex]P.E._{max}[/tex] + 0 =

M.E. = [tex]\mathbf{P.E._{max}}[/tex]

Similarly, at the bottom of the dam, the height, h = 0, therefore, being proportional to the height, P.E. = 0, and the velocity is maximum, and at the bottom, we have;

M.E. = 0 + [tex]K.E._{max}[/tex]

The first chart, water is halfway down the dam

At the halfway down therefore, we have;

P.E. = (1/2)·[tex]\mathbf{P.E._{max}}[/tex]

M.E. = [tex]P.E._{max}[/tex] = (1/2)·

∴ K.E. = [tex]P.E._{max}[/tex] - (1/2)·

Therefore the first chart, water is halfway down the dam;

Halfway, K.E. = (1/2)·[tex]\mathbf{P.E._{max}}[/tex] = P.E.

∴ K.E. = P.E.  as shown on the chart

The second chart, water has reached the turbine

Water reaches the turbine at the bottom, and as explained above, we get;

M.E. = 0 + [tex]K.E._{max}[/tex]

∴ M.E.≈ [tex]K.E._{max}[/tex]

Therefore, when water has reached the turbine at the bottom of the dam, the kinetic energy is approximately proportional to the total mechanical energy as shown in the chart

The third chart, water is at the top of the dam

Here as shown above, we have;

The total mechanical energy, M.E. ≈ [tex]\mathbf{P.E._{max}}[/tex] as shown on the chart

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Doppler frequency, the other car hear before they pass each other is 668.68 Hz.

Frequency is the number of occurrences of a repeating event per unit of time.

The Doppler effect is the change in frequency of a wave in relation to an observer who is moving relative to the wave source.

According to the Doppler Effect, the frequency observed is

  [tex]fo=fs\frac{v+v_{o} }{v-v_{s} }[/tex]

[tex]f_{o}=595\frac{343+20 }{343-20 }\\f_{o} = 668.68 Hz[/tex]

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Answer:

cần cung cấp 70 độ vì nước sôi ở 100°C

Explanation:

We know

[tex]\boxed{\sf Spring\:constant(K)=\dfrac{F}{x}}[/tex]

[tex]\\ \sf\longmapsto K=\dfrac{1}{0.5}[/tex]

[tex]\\ \sf\longmapsto K=2N/m[/tex]

Radiation is energy that comes from a source and travels through space at the speed of light. This energy has an electric field and a magnetic field associated with it, and has wave-like properties. You could also call radiation “electromagnetic waves”.

cdc

Answer:

But negative acceleration means that the rate of change of velocity is negative or velocity decreases. Example: (1) When we apply brakes in a moving car, then negative acceleration acts on it and the car stops. (2) When we throw a ball upwards, then also negative acceleration acts on it.

Explanation:

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MATHEMATICALLY A NEGATIVE ACCELERATION MEANS YOU WILL SUBTRACT FROM THE CURRENT VALUE OF THE VELOCITY.

Answer:

If effort distance was 4 times, efficiency would be 100%.

Since it takes 5 times for effort distance, efficiency drops to output/input

output is 1*F

input is (1/4*F)*5

so: F/1/5*F/4 = 4F/5F = .8 or 80%

The efficiency of the lever is 80%.

To calculate the efficiency of the lever, we can use the formula for mechanical advantage and efficiency.

Mechanical Advantage (MA) is the ratio of the load (L) to the effort (E) in a lever system:

MA = Load / Effort

Given that the load is four times the effort applied:

Load = 4 * Effort

Also, the effort distance (dEffort) is five times the load distance (dLoad):

dEffort = 5 * dLoad

Now, we can write the formula for efficiency (η) of a lever system:

Efficiency (η) = (Mechanical Advantage / Ideal Mechanical Advantage) * 100%

The Ideal Mechanical Advantage (IMA) is the ratio of the effort distance to the load distance:

IMA = dEffort / dLoad

Substitute the given values into the IMA equation:

IMA = (5 * dLoad) / dLoad

IMA = 5

Now, we can calculate the Mechanical Advantage (MA) using the relationship between the load and effort:

MA = Load / Effort

MA = (4 * Effort) / Effort

MA = 4

Finally, we can calculate the efficiency (η):

Efficiency (η) = (Mechanical Advantage / Ideal Mechanical Advantage) * 100%

η = (4 / 5) * 100%

η = 0.8 * 100%

η = 80%

The efficiency of the lever is 80%.

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Tomando en cuenta la Ley de Charles y la condiciones dentro del recipiente, tenemos las siguientes conclusiones con respecto al volumen del recipiente:

1) El volumen inicial del gas es 144.203 mililitros.

2) El volumen final del gas es 386.986 mililitros.

La Ley de Charles establece que el Volumen de un gas es directamente proporcional a su Temperatura, basados en este hecho, podemos resolver los problemas en cuestión mediante la siguiente relación matematica:

[tex]\frac{V_{1}}{T_{1}} = \frac{V_{2}}{T_{2}}[/tex] (1)

Donde:

[tex]V_{1}[/tex] - Volumen inicial, en mililitros.

[tex]V_{2}[/tex] -  Volumen final, en mililitros.

[tex]T_{1}[/tex] - Temperatura inicial, en Kelvin.

[tex]T_{2}[/tex] - Temperatura final, en Kelvin.

1) Si sabemos que [tex]V_{2} = 150\,mL[/tex], [tex]T_{2} = 388.15\,K[/tex] and [tex]T_{1} = 373.15\,K[/tex], entonces el volumen inicial del gas es:

[tex]V_{1} = \frac{T_{1}}{T_{2}}\times V_{2}[/tex]

[tex]V_{1} = \frac{373.15\,K}{388.15\,K}\times 150\,mL[/tex]

[tex]V_{1} = 144.203\,mL[/tex]

El volumen inicial del gas es 144.203 mililitros.

2) Si sabemos que [tex]T_{1} = 473.15\,K[/tex], [tex]V_{1} = 350\,mL[/tex] and [tex]T_{2} = 523.15\,K[/tex], entonces el volumen final del gas es:

[tex]V_{2} = \frac{T_{2}}{T_{1}}\times V_{1}[/tex]

[tex]V_{2} = \frac{523.15\,K}{473.15\,K}\cdot 350\,mL[/tex]

[tex]V_{2} = 386.986\,mL[/tex]

El volumen final del gas es 386.986 mililitros.

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Answer:

1) The kinetic energy of the object after it drops for 2.0 seconds is approximately 384.9 Joules

2) The potential energy of the object after it drops for 2.0 seconds is approximately 204 J

Explanation:

1) The given mass of the object, m = 2.0 kg

The height from which the object is dropped, h = 30 m

The kinetic energy of the object after it drops for 2.0 seconds = Required

Kinetic energy, K.E. = (1/2)·m·v²

Where;

v = The velocity of the object

The kinematic equation for finding the velocity of the object is presented as follows;

v = u + g·t

Where;

u = The initial velocity of the object = 0

g = The acceleration due to gravity of the object ≈ 9.81 m/s²

t = The time of motion of the object = 2.0 seconds

∴ The velocity after 2 seconds, v ≈ 0 + 9.81 m/s² × 2 s = 19.62 m/s

The kinetic energy, K.E. after 2 seconds as the object drops is given as follows;

[tex]K.E._{(after \ two \ seconds)}[/tex] = (1/2) × 2.0 kg × (19.62 m/s)² = 384.9444 J ≈ 384.9 J

2) The total energy, M.E. of the object at the top, h = 30 m, u = 0, is given as follows;

The total mechanical energy, M.E. = P.E. + K.E.

M.E. = m·g·h + (1/2)·m·u²

∴ M.E. = 2.0 kg × 9.81 m/s² × 30 m + 0 = 588.6 J

M.E. = 588.6 J

Given that the total mechanical energy, M.E., is constant, we have;

At 2.0 seconds, M.E. = 588.6 J , K.E. ≈ 384.9 J, P.E. = M.E. - K.E.

∴ P.E. = 588.9 J - 384.9 J ≈ 204 J

The potential energy after it drops 2.0 seconds, P.E. ≈ 204 J

Answer:

0.80 m

Explanation:

Neglecting friction, the total mechanical energy of the pendulum is constant.

E = K + U where K = kinetic energy and U = potential energy.

At its release point of 0.80 m, the pendulum bob has a mechanical energy which is equal to its potential energy, since, its initial kinetic energy is zero. By the time the bob swings to the other end, it has a mechanical energy equal to it initial potential energy since total energy is conserved.

Neglecting friction, the pendulum bob would swing back to its original height of 0.80 m since the total mechanical energy is conserved and at its highest point, it is purely potential energy.

So, the height the pendulum bob swings to after release from a height of 0.80 m neglecting fiction is 0.80 m.

Answer:

Explanation:

By being close to an atom that will gladly take the electrons being offered.

Suppose you are talking about Be. It is in the second column. It has two outer electrons that can be given away. It will not give away one of the two remaining electrons because they are too close to the + nucleus.

Along comes a Fluorine atom. It has 7 electrons in its outer ring. The chemistry of the situation allows it to take on one of the two electrons Be is offering. It is all a matter of charges and attractions.

Another Fluorine atom will take on the remaining electron from the Be. The outer ring cannot take on more than 1 electron, but that is enough

Option ( iv ) is the correct answer.

A vector quantity the physical quantity that has both direction as well as magnitude.

The magnitude (size or numerical value) and the direction.

Hope this helps!!! :)

7351.35Hz

f0= v-Vo/v-Vs × FSA

= 340-0 /340+30 ×8000

= 340/370× 8000

= 7351.35hz

[tex]\boxed{\sf W=Fscos\Theta}[/tex]

[tex]\\ \sf\longmapsto W=150(50)cos 60[/tex]

[tex]\\ \sf\longmapsto W=7500\times \dfrac{1}{2}[/tex]

[tex]\\ \sf\longmapsto W=3750J[/tex]

Almost 3 times fast than normal pulley system

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Lithium element contains one electron therefore valence electron will be one.  

The highest level of energy is due to valence electrons which are available to the atom.

The calcium has 2 valence electrons which has electrons with high energy.

These energy will be used by the electron during the chemical reaction, and they will either lose or gain valence electron.

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Answer:

calcium

Explanation:

2 electron