Which property of air makes it effective in protecting firefighters?

The reason why the book does not slide off the teacher's hand when she tilts her hand forward is because of the force of friction between the surfaces of the book and the teacher's hand.

Friction is a force that resists the motion between two surfaces that are in contact. When the book is resting on the teacher's hand, the surfaces of the book and the hand are in contact with each other. When the teacher tilts her hand forward, the force of gravity tries to pull the book downward, but the force of friction between the book and the hand acts in the opposite direction, preventing the book from sliding off the hand.

The amount of friction between two surfaces depends on a few factors, such as the type of materials in contact, the roughness of the surfaces, and the force pressing the surfaces together. The force of friction increases as the force pressing the surfaces together increases. In this case, the weight of the book pressing down on the teacher's hand increases as the hand tilts forward, which increases the force of friction between the book and the hand, keeping the book in place.

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Standard distance indicators, CEPHEID VARIABLES AND TYPE Ia SUPERNOVAE, since their intrinsic luminosity is fairly well known.

Cepheid variables are a type of pulsating stars that exhibit a relationship between their period of pulsation and their intrinsic luminosity. By measuring the period of pulsation, astronomers can determine the luminosity of the Cepheid variable, which in turn allows them to calculate the distance to the object.

Type Ia supernovae, on the other hand, are a specific type of stellar explosion that occurs in binary star systems. These supernovae occur when a white dwarf star accretes matter from its companion star, causing it to exceed a critical mass and undergo a runaway nuclear fusion reaction.

The resulting explosion releases an immense amount of energy, and because the intrinsic luminosity of Type Ia supernovae is well understood, they can be used as standard candles to determine distances in the universe.

Both Cepheid variables and Type Ia supernovae have played crucial roles in measuring cosmic distances and contributing to our understanding of the scale and expansion of the universe.

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Answer:

temperature inside the balloon so it is warmer than the surrounding air

Explanation:

For the balloon to get an uplift , it should be lighter than air . That means the density of the gas inside should be less than the density of air outside . only then ,  weight of the balloon plus the weight of the air inside balloon  will become less than the weight of displaced air outside . This can be achieved by warming up the air inside. Its temperature must exceed that of outside air.

The option that best explain how the pilot can make the balloon rise is option D. The pilot can increase the temperature inside the balloon so it is warmer than the surrounding air

An object will float in air when the density of the object is lower than the density of the air.

Increase in temperature of a gas decreases the density of the gas.

For the pilot to make the balloon rise, he must find a way to make the balloon more lighter than air. To do this, he has to increase the temperature of the balloon.

In this question, the pilot can increase the temperature inside the balloon so it is warmer than the surrounding air in order for the balloon to quickly rise several feet higher above some trees in distance.

Therefore, option D best explain how the pilot can make the balloon rise.

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Answer:

what?

Explanation:

theres nothing

Answer:

Hope it helped brainiest plz and thank you!!!!!!1

Explanation:

3. If humans could unleash genetic modifications upon mosquitos that would eradicate the species entirely, should they do it?

No, they should not eradicate the mosquitos because they are part of the food chain for some animals.

Tony's Arc Reactor serves as the power source for the Repulsors, which are located in the palms of the armor.Originally intended to stabilize the flight of the armor and add more agility.

Hydrogen is the gas utilized, and a sophisticated suit like Iron Man can easily extract it from the air by electrolysis. The water was condensed even as suit overpressurized ram air into form water, as well as the hydrogen gas is formed and sent right to the rocket boots.

The nuclear core which Tony Stark creates and implants in his heart to save his life also fuels all of his armor.In essence, it is a very energy-dense battery.

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The speed of the object at time t = 2 seconds is 1.00 m/s.

To determine the speed of the object at a given time, we need to find the magnitude of its velocity vector at that time.

Given:

Position vector r(t) = [2.0 m + (5.00 m/s)t] + [3.0 m - t² m]

To find the velocity vector v(t), we take the derivative of the position vector with respect to time:

v(t) = d[r(t)]/dt

v(t) = d/dt [2.0 m + (5.00 m/s)t] + d/dt [3.0 m - t² m]

v(t) = 5.00 m/s + d/dt [3.0 m - t² m]

The derivative of a constant term is zero, so the velocity vector simplifies to:

v(t) = 5.00 m/s - d/dt (t²) m

Taking the derivative of t² with respect to time:

v(t) = 5.00 m/s - 2t m/s

Now, we can calculate the magnitude of the velocity vector (speed) at a specific time t:

Speed = |v(t)| = |5.00 m/s - 2t m/s|

To find the speed at a given time, substitute the appropriate value of t into the expression and calculate the magnitude.

For example, if t = 2 seconds:

Speed = |5.00 m/s - 2(2 s) m/s|

      = |5.00 m/s - 4 m/s|

      = |1.00 m/s|

      = 1.00 m/s

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A. The energy stored in the inductor is 12.6 mJ.

B. The inductor would have to carry 3.66 A to store 0.60 J of energy.

C. Yes, it's reasonable for ordinary laboratory circuit elements.

A) To calculate the energy stored in an 11.2 mH inductor carrying a 1.50 A current, we can use the formula:
Energy = (1/2) * L * \(I^2\)
Where L is the inductance (11.2 mH or 0.0112 H) and
I is the current (1.50 A).

Energy = (1/2) * 0.0112 * \((1.50)^2\)
Energy = 0.0126 Joules

B) To find the current required to store 0.60 J of energy in the inductor, we can rearrange the energy formula:
I = \(\sqrt{2 * Energy / L}\)

Plugging in the given energy (0.60 J) and inductance (0.0112 H):
I = \(\sqrt{2 * 0.60 / 0.0112}\)
I ≈ 3.66 A

C) Considering the current found in part B (3.66 A), it is reasonable for ordinary laboratory circuit elements. Typical laboratory circuits can handle currents in the range of a few Amperes without significant issues.

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Answer: 4 kg

Explanation:

Ke=1/2MV^2

plug in the kinectic energy and solve for M

50=1/2(M) (5^2)

M= 4

According to Newton's law, action and reaction are equal and opposite.

According to the Newton's third law of motion, action and reaction are equal and opposite. As such, when the arrow hits the vertical wood board, the board exerts some force on the arrow.

We can not determine the magnitude of this force numerically because the question is incomplete.

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Answer:

newtons law action and reaction are equal and opposite

Explanation:

GPS readings of longitude and latitude are based on wgs84. Option 3.

GPS readings of longitude and latitude are based on the WGS84 (World Geodetic System 1984) coordinate reference system.

WGS84 is widely used as the standard coordinate system for GPS (Global Positioning System) positioning and navigation.

It provides a consistent and globally recognized framework for accurately determining and representing locations on Earth's surface.

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Answer:

The horizontal distance the pumpkin will travel after it slips from the eagle is 17.02 m

Explanation:

Given;

height above the ground, h = 16.4 m

speed of the eagle, v = 9.3 m/s

The time it will take the pumpkin to fall at the given height is calculated as;

\(t = \sqrt{\frac{2h}{g} }\\\\t = \sqrt{\frac{2*16.4}{9.8} }\\\\t = 1.83 \ s\)

The horizontal distance traveled at this time is given by;

x = vt

x = (9.3)(1.83)

x = 17.02 m

Therefore, the horizontal distance the pumpkin will travel after it slips from the eagle is 17.02 m

The amount of heat (H) produced is given by the joule’s law of heating as H= Vlt

Where,

Current, I = 5 A

Time, t = 30 s

Voltage, V = Current x Resistance = 5 x 20 = 100V

H= 100 x 5 x 30 = 1.5 x 10⁴ J.

Therefore, the amount of heat developed in the electric iron is 1.5 x 10⁴J.

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Answer:

Zero I think I'm not sure

Answer:

500ms times 2 would be when the ball reaches the max horizontal distance.

Then to find the angle, use the formula of time to reach max height t = u sin theta / g . With t being the max height time 500ms, u being 10m/s

For initial vertical velocity just use u sin theta.

The max horizontal height is "10 meters" and the initial vertical velocity is "4.9 m/s".

Given:

Horizontal velocity,

Time,

At max height,

(a)

→ Time to flight (T) will be:

= \(2t\)

= \(2\times 0.5\)

= \(1 \ second\)

→ Horizontal distance will be:

= \(V_x\times T\)

= \(10\times 1\)

= \(10 \ meters\)

(b)

→ The initial vertical velocity will be:

\(V_{yf} = V_y +gt\)

   \(0 = V_y - 9.8\times 0.5\)

  \(V_y = 4.9 \ m/s\)

Thus the above answers are correct.

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you can optimize the maximum range performance of a turbojet aircraft as its weight reduces.

Maximum range performance of a turbojet aircraft as the aircraft weight reduces, you should follow this procedure:
1. Optimize the aircraft's cruise altitude: As the weight reduces due to fuel consumption, adjust the altitude to maintain the optimal lift-to-drag ratio.
2. Adjust the aircraft's speed: To maintain the maximum range performance, adjust the airspeed according to the changing weight to ensure that you're flying at the best lift-to-drag ratio speed.
3. Monitor fuel consumption: Continuously monitor the fuel consumption to determine when you need to make adjustments to altitude and airspeed.
4. Optimize the engine's thrust-specific fuel consumption (TSFC): Ensure the engine is operating at its optimal TSFC to achieve the best fuel efficiency, which contributes to the maximum range performance.
By following this procedure, you can optimize the maximum range performance of a turbojet aircraft as its weight reduces.

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The pushing force described in the question is called compressive force. It is a force that acts in the opposite direction of tension, meaning it tends to squeeze or shorten an object along the dimension coinciding with the line of action of the force.

Compressive force is a type of contact force that acts perpendicular to the surface of an object.
It applies pressure on the object, causing it to deform or compress along the direction of the force.
The magnitude of the compressive force depends on various factors, such as the applied load and the properties of the object, like its elasticity.
Compressive forces can be found in various situations, such as when you push down on a spring or when you squeeze a sponge.
In engineering and architecture, compressive forces are crucial to consider when designing structures that need to support weight or withstand external pressure.
Compressive forces can cause objects to buckle, collapse, or undergo structural failure if they exceed the object's capacity to withstand compression.

A compressive force is a pushing force that tends to squeeze or shorten an object along the direction of the force. It is important to consider compressive forces in various fields to ensure the stability and integrity of objects and structures.

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The correct answer is e. None of the above alternatives gives a true statement. None of the statements in options a, b, c, and d are true when it comes to a modulus M over a ring R having a finite basis.

When a modulus M can be formed entirely from a finite set of elements, the modulus M is said to be finitely generated. M's finite basis does not, however, automatically imply that M is finitely generated. A basis is a set of linearly independent elements, and it might not be enough to produce all of the components of the modulus.

According to the assertion in option b, M must include nonzero items of nonzero order if it has a finite basis. This is untrue, though. The smallest positive number k, such that the element raised to the power of k equals the identity element, is referred to as the order of an element.

According to option c, every non-null element in a modulus with a finite basis has a null. Nevertheless, this claim is likewise untrue. It is possible for a modulus with a finite basis to have non-null elements without a null element.

According to option d, a ring R is a body, or a field, and only then can a modulus have a finite basis. However, this assertion is also untrue. Even though the ring R is not a field, a modulus can nonetheless have a finite basis. None of the given alternatives provides a true statement about a modulus M over a ring R having a finite basis.

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Part A: The electric potential V at a point on the disk's axis a distance x from the center of the disk is given by:

V = σ/2ε₀ × \((R^{2}/(x^{2} +R^{2} )^{1/2})\)

Part B: After calculating for −∂V/∂x we get:

-∂V/∂x = σR²x/2ε₀\((x^{2}+R^{2})^{3/2}\)

Part A:

The disc can be split into a number of thin, concentric rings in order to compute the electric potential V at a point on its axis that is located x distance from the disk's centre.

Each ring's potential is determined by:

\(V_{ring}\) = 1/4πε₀ × (\(Q_{ring}\) /  \((x^{2} +R^{2} )^{1/2}\))

where

\(Q_{ring}\) is the charge of the ring and

ε₀ is the permittivity of free space.

Since

the disk has uniform surface charge density σ, the charge on each ring is given by:

\(Q_{ring}\) = σ × 2πr × dr

where

r is the radius of the ring and

dr is its thickness.

By substituting \(Q_{ring}\) into the expression for \(V_{ring}\), we get:

\(V_{ring}\) = 1/4πε₀ × (σ × 2πr × dr / \((x^{2} +R^{2} )^{1/2}\))

By integrating across all the rings, it is possible to get the total potential V at any point along the axis of the disc:

V = ∫V_ring

V = ∫(1/4πε₀ × (σ x 2πr × dr / \((x^{2} +R^{2} )^{1/2}\))

V = σ/2ε₀ × ∫(r / \((x^{2} +R^{2} )^{1/2}\)) dr from 0 to R

By evaluating the integral and simplifying, we get:

V = σ/2ε₀ × [\((R^{2}/(x^{2} +R^{2} )^{1/2})\) - \((0/(x^2+0^2)^{1/2})\)]

V = σ/2ε₀ × \((R^{2}/(x^{2} +R^{2} )^{1/2})\)

Therefore, the electric potential V at a point on the disk's axis a distance x from the center of the disk is given by:

V = σ/2ε₀ × \((R^{2}/(x^{2} +R^{2} )^{1/2})\)

Part B:

To find the value of −∂V/∂x,

The derivative of the equation for V with regard to x must be taken:

∂V/∂x = -σR²x/2ε₀\((x^{2}+R^{2})^{3/2}\)

Hence, the expression for −∂V/∂x is:

-∂V/∂x = σR²x/2ε₀\((x^{2}+R^{2})^{3/2}\)

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The electric field strength on the surface of a hollow metal sphere of radius 11.22 cm carrying a charge of 2.16 uC is 2.17 × 10⁵ N/C

To calculate electric field strength E, we use the formula:

E = Q / 4πεr²

Here, Q = 2.16 μ

C = 2.16 × 10⁻⁶ C

The radius r of the hollow metal sphere is 11.22 cm = 0.1122 m.

The electric constant

ε = 8.854 × 10⁻¹² F/m²

Using the above formula:

E = Q / 4πεr² = (2.16 × 10^-6 C) / [4π (8.854 × 10^-12 F/m²) (0.1122 m)²] = 2.17 × 10^5 N/C

Therefore, the electric field strength E on the surface of the hollow metal sphere is 2.17 × 10^5 N/C.

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Some examples of significant figures that can help you better understand them are:

Furthermore, some extra tips are:

This refers to the digits that carry meaning contributing to its measurement resolution and each of the digits of a number that are used to express it to the required degree of accuracy, starting from the first non-zero digit.

Hence, we can see that:

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Answer:

it can be calculated by measuring the final distance away from a point, and then subtracting the initial distance

Answer:

Explanation:

actually , the acceleration due to gravity depends on the distance from it's center of the earth.

when the distance from the earth increases , the acceleration due to gravity decreases as a result . The value of gravity in space is zero.

Answer:

when you jump, your legs apply force on the ground that applies an equal and opposite reaction that make you jump

(a) The distance From A to B to M to N is 22 m, the displacement is 22 m, the speed is 4.4 m/s and the average velocity is 4.4 m/s.

(b) The distance From C to A to G to D is 24 m, the displacement is 2 m, the speed is 4.8 m/s and the average velocity is 0.4 m/s.

(c) The distance From J to I to E to H is 16 m, the displacement is -2 m, the speed is 3.2 m/s and the average velocity is -0.4 m/s.

(d) The distance From F to B to K to F is 32 m, the displacement is 0 m, the speed is 6.4 m/s and the average velocity is 0 m/s.

The distance traveled by the object is calculated as follows;

Distance From A to B to M to N

From A to B to M to N = 3 + 18 + 1 = 22

Distance From C to A to G to D

= 5 + 13 + 6

= 24

Distance From J to I to E to H

= 1 + 8 + 7

= 16

Distance from F to B to K to F

= 8 + 16 + 8

= 32

The displacement of the object is calculated as follows;

displacement = final position - initial position

Displacement From A to B to M to N

= 11 - (-11)

= 22

Displacement from C to A to G to D

= D - C

= - 4 - (-6)

= 2

Displacement from J to I to E to H

= H - J

= 5 - 7

= - 2

Displacement From F to B to K to F

= F - F

= 0

The speed of the object is calculated as follows;

speed = total distance/total time

Speed of the object from A to B to M to N

= 22/5 = 4.4 m/s

Speed of the object from C to A to G to D

= 24/5

= 4.8 m/s

Speed of the object from J to I to E to H

= 16/5

= 3.2 m/s

Speed of the object from F to B to K to F

= 32/5

= 6.4 m/s

The average velocity of the object is calculated as follows;

Average velocity from A to B to M to N

= 22/5

= 4.4 m/s

Average velocity of the object from C to A to G to D

= 2/5

= 0.4 m/s

Average velocity of the object from J to I to E to H

= -2/5

= -0.4 m/s

Average velocity of the object from F to B to K to F

= 0

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Answer:

¿Qué sistemas? ¿Hubo otra parte de la pregunta que quizás hayas olvidado hacer?

Explanation:

In english:

(question) In the systems listed below, indicate where you think the energy they use comes from and clarify whether they only use or can accumulate

(answer) What systems? Was there another part of the question you might've forgotten to put?

Answer:

A

Explanation:

Answer:

Ottoman

Explanation:

siri told me after I asked

The steam engine does 60 kilojoules of useful work out of the 300 kilojoules of energy supplied, since its efficiency is only 20%.

What is the amount of useful work done by a steam engine with 20% efficiency, if the input energy is 300 kilojoules?

The efficiency of a steam engine is a measure of how much of the input energy is converted into useful work. In this case, we know that the efficiency of the steam engine is 20%, which means that only 20% of the input energy is converted into useful work.

To find out how much work the steam engine does, we use the formula:

Useful work = Input energy x Efficiency

In this formula, the input energy is the amount of energy that is supplied to the steam engine, and the efficiency is the percentage of that energy that is converted into useful work.

So, in this case, we know that the input energy is 300 kilojoules, and the efficiency is 20%. we get:

Useful work = 300 kilojoules x 0.20

Useful work = 60 kilojoules

Therefore, the steam engine does 60 kilojoules of useful work. This means that out of the 300 kilojoules of energy that were supplied to the steam engine, only 60 kilojoules were converted into useful work, and the remaining 240 kilojoules were lost as heat or other forms of energy.

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