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which two changes to a metal wire both increases resistance? the answer is B but why ?

Answer:

Following are the solution to this question:

Explanation:

Given value:

[tex]m_s= 4.00 \times 10^{-2} \ kg \\\\L_v=2256 \times 10^{3} \ \frac{J}{kg}\\\\m_w= 0.2 \ kg\\\\\Delta T= 50^{\circ}[/tex]

In point A:

[tex]Q_{Steam}=m_s \ L_v[/tex]

            [tex]=0.04 \times 2256 \times 10^{3}\\\\=9.02 \times 10^4 \ J[/tex]

[tex]Q_{water}= m_w \ c_w \ \Delta T\\\\[/tex]

           [tex]=0.2 \times 4190 \times 50\\\\=4.19 \times 10^4 \ J[/tex]

[tex]Q_{steam}> Q_{water}[/tex], that's why the final temperature is [tex]= 100^{\circ}[/tex]

In point B:

[tex]\to \Delta m_s L_v=m_w\ c_w \Delta T\\\\\to \Delta m_s \times 2256\times 10^3= 0.2 \times 4190 \times 50\\\\\to \Delta m_s= 1.86 \times 10^{-2} \ kg\\\\\to m_s = 2.14 \times 10^{-2} \ kg\\\\\to liquid \ left = 0.2+ 2.14 \times 10^{-2} = 2.34 \times 10^{-2} \\[/tex]

Answer:

Explanation:

speed = distance / time

          = 15 meters / 3 seconds

          = 5 meter / sec.

Answer:5/sec

Explanation:

Answer: R=40 Ω

Explanation: [tex]P=I^{2} R[/tex]

R=1000/ (25)=40

Answer:

i guss its A

Explanation:

Answer:

1) The force Christian can exert on his bicycle before picking up the the cargo is 529.74 N

2) The force Christian can exert on his bicycle after picking up the the cargo is 647.46 N

Therefore, Christian has to exert more force on his bike after picking up the cargo

Explanation:

The given parameters are;

The mass of Christian and his bicycle = 54 kg

The mass of the cargo = 12 kg

1) The force Christian can exert on his bicycle before picking up the the cargo = Mass of Christian and his bicycle × Acceleration due to gravity

∴ The force Christian can exert on his bicycle before picking up the the cargo = 54 kg × 9.81 m/s² = 529.74 N

2) The force Christian can exert on his bicycle after picking up the the cargo = (54 + 12) kg × 9.81 m/s² = 647.46 N

Therefore, Christian has to exert more force on his bike after picking up the cargo.

Answer:

9 s.

Explanation:

The following data were obtained from the question:

Time (t) taken to reach the maximum height = 4.5 s

Time of flight (T) =?

The time of flight (T) is simply defined as the total time spent by the ball in the air. Mathematically, it defined as twice the time taken (t) to reach the maximum height i.e

T = 2t

With the above formula, we can obtain the time of flight as follow:

Time (t) taken to reach the maximum height = 4.5 s

Time of flight (T) =?

T = 2t

T = 2 × 4.5

T = 9 s

Thus, the time of flight of the ball is 9 s.

Answer:

    m v ´- MV = (m + M) v ’

Explanation:

If the astronaut initially has a speed v the satellite has a speed V, we can define a system that is formed by the two bodies, therefore the forces during the collision are internal, so the momentum is conserved

initial instant. Before the crash

          p₀ = m v - MV

final instatne. After the crash, we have two cases

1) inelastic shock

          m_f = (m + M) v '

          p₀ = p_f

         m v ´- MV = (m + M) v ’

2) elastic collision with the astronaut's velocity, zero in this case the moment remains

        m v - MV = mv ’+ Mv’

also the kinetic energy is conserved

       mv'2 + M V2 = mv'2 + m v'2

with these two equations we can find the speed of the cars

Answer:

B. silicate rocks and metals

Terrestrial planets, such as Earth, are primarily composed of silicate rocks and metals. The correct answer is b. silicate rocks and metals.

Silicate rocks, which are made up of silicon and oxygen, are the dominant building blocks of these planets. They include minerals like quartz, feldspar, and mica. Terrestrial planets contain significant amounts of metals such as iron, nickel, and other heavy elements. These metals are found in the planet's core, providing structural strength and contributing to the planet's magnetic field.

This composition differentiates terrestrial planets from gas giants like Jupiter and Saturn, which are predominantly composed of hydrogen and helium. The combination of silicate rocks and metals forms the solid, rocky surfaces that characterize terrestrial planets.

Therefore, The correct answer is b. silicate rocks and metals.

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Answer:

A divergent boundary occurs when two tectonic plates move away from each other. Along these boundaries, earthquakes are common and magma (molten rock) rises from the Earth's mantle to the surface, solidifying to create new oceanic crust. When two plates come together, it is known as a convergent boundary.

Explanation:

Answer: I think the answer is d

Explanation: sry if wrong

Answer:

a

Explanation:

it increases with increasing height

Answer:

285

Explanation:

read and alot jbgdxtffhgdae

Answer:

Both the initial and final substances are composed of atoms because all matter is composed of atoms. According to the law of conservation of matter, matter is neither created nor destroyed, so we must have the same number and kind of atoms after the chemical change as were present before the chemical change.

Explanation:

Answer:

The law of conservation of atoms is simple but it has a great affect. An atom cannot be destroyed by such a force. Matter/atoms can't be created by any means. An atom exits only by nature and not by force.

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Answer:

We want to have an acceleration of:

A = 1.5*g = 1.5*9.8m/s^2  = 14.7 m/s^2

When the rim is moving at 37m/s while spinning.

Now, in circular motion we have two accelerations.

Tangential acceleration, that is the one related to the change of speed, as we have a speed of 37m/s, we can assume that is constant, then the tangential acceleration is zero.

Centripetal acceleration, is the one related to the change in direction, is perpendicular to the velocity vector and is the one that allows the circular motion.

I suppose that in this problem we want to have a  centripetal acceleration of 14.7m/s^2

The equation for the centripetal acceleration is:

Ac = v^2/r

Where v = velocity and r = radius.

then we must solve:

14.7m/s^2 = (37m/s)^2/r

r = (37m/s)^2/14.7m/s^2 = 93.13 m

b=36•3

momentum=mass×velocity

The total momentum of the given system is equal to zero. Therefore, option (C) is correct.

The linear momentum can be described as the product of the mass times the velocity of that object. Conservation of momentum is a property of an object as the total amount of momentum stays the same.

According to the law of conservation of momentum, the sum of the momentum before and after the collision of the objects must be equal.

m₁ u₁ + m₂ u₂ = m₁ v₁ + m₂v₂

where u₁ and u₂ are initial speed while v₁ & v₂ is final speed and m₁ and m₂ is the mass of the collided objects.

The first ball, m = 8.52 g and v = 2.13 m/s

The momentum of the first ball = 18.15 g.m/s

The second ball is moving in the opposite direction w.r.t. first ball,

The second ball, m = 8.52 g and v = - 2.13 m/s

The momentum of the first ball = - 18.15 g.m/s

The total momentum  of the system = 18.15 + (-18.15) = 0

Therefore, the total momentum of the given system is zero.

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Answer: Terminal velocity is achieved, therefore, when the speed of a moving object is no longer increasing or decreasing; the object's acceleration (or deceleration) is zero.

Explanation:.

Answer: Terminal velocity is achieved, therefore, when the speed of a moving object is no longer increasing or decreasing; the object's acceleration (or deceleration) is zero.

As others have said, 8 seconds to get to 90% of terminal velocity. But if you're falling from outer space, you could reach speeds much higher than terminal velocity, and slow down when you reach the atmosphere. If coming in from a long distance, you'll burn up like a meteorite.

Explanation:

Answer:

Protection – Protect the wounded area with a support or something similar.

Rest – Do not continue to exercise while your wound is healing. It may take a few weeks or months to recover. You may need crutches or a sling.

Ice – Wrap a bag of ice or a bag of frozen peas in a towel and apply it to the wounded area for 15–20 minutes every two to three hours.

Compression – Apply elastic compression bandages to the wounded area during the day to reduce swelling.

Elevation – Make sure the injured body part is elevated above the height of your heart as much as possible to help reduce swelling.

Explanation:

Just did it.

Answer:

The five-step process for treating a muscle or joint injury such as an ankle sprain is called "P.R.I.C.E." which is short for Protection, Rest, Ice, Compression, and Elevation).

It can be used even by someone without first-aid training, and should be used immediately when an injury occurs – the earlier, the better – while further medical attention is being sought.

If the athlete experiences too much pain during the process, stop immediately.

"P" is for Protection

Protect the injured person and the area being treated but also protect yourself. If the injury occurs on the sports field, stop the game.

Protect the area being treated with a splint if possible.

If the athlete can move, carefully move them to a safer area using a stretcher or a crutch, but if there is any doubt, do not move the injured athlete.

"R" is for Rest

When a child is injured, the body responds in an effort to defend, localize, protect, and clean up the injured area, a response called inflammation. At the time of injury small blood vessels at the injury site rupture and cause tissue bleeding, which, in turn, can cause bruising and swelling.

Explanation:

There are five warning signs of inflammation:

Pain

Redness;

Tissue hotness;

Swelling, and

Loss of function.

Not every injury exhibits all these signs, but if your child is in pain then it is important to stop exercising immediately to avoid further damage.

"I" is for Ice

As soon as possible after injury, begin applying ice continuously for the first 15-20 minutes to decrease swelling and pain.

An ice bag can be applied directly to the skin (except on the outside of the knee) unless the child has a known cold allergy.

The safest form of icing is to use a plastic bag with ice cubes or crushed ice, or instant cold packs. Do not use “blue ice” or “gel packs”.

While icing will be uncomfortable at first, in 2 to 3 minutes, the skin will go numb and the ice bag will feel more comfortable.

If the child is very uncomfortable with ice bag, then a barrier like a wet towel can be placed between the ice and skin.

The ice bag can be secured in place using an elastic bandage, but the compression should not be too tight.

During the application of the ice, ask the child to wiggle their fingers/toes and monitor tissue around area that is being iced to ensure that they are not experiencing a lost of sensation.

Icing for 15-20 minutes with an ice bag is unlikely to cause nerve damage or frostbite; however, any loss of sensation and any changes in tissue coloration in areas other than the area that is being iced indicate that the application is no longer safe.

Because ice and plastic bags are so important, make sure that someone brings these to every practice and game. Better yet, to be on the safe side, bring your own!

Answer:

R

Explanation:

Her distance from home and Time increase

the stops when she gets to the library

then her distance from home decreases while her time increases

Answer:

what is the direction of the sum of these two vectors?

Answer:

69.6

Explanation:

Ax= 0

Ay= 63.5

Bx= 101 cos 57= 55.009

By= 101 sin 57= 84.706

Tan-1 = (84.706/55.009)

         = 69.6

Air is cooled and

becomes denser.

Denser air sinks.

The process repeats, producing a (i wasn't sure about this one)

Air is heated and becomes less dense.

Less dense air rises.

hope this helps!

Answer:

the acceleration of gravity is 1.62

Explanation:

w=mg

141=87g

141/87=87g/87

1.62=g

Answer:

C. increase the number of wraps of wire around the core.

E. Connect a second battery in the circuit.

Explanation:

got the question current on a p e x

increase the number of wraps of wire around the core and Connect a second battery in the circuit are the two actions would strengthen an electromagnet.

The  distribution electrical power  through wires in a perfect manner inside a building or a room with better load control is known as electrical wiring.

Different types of wiring such as Tee system or Joint box system where the connection of appliances is done with this wiring, which does not  consume too much cable size.

Loop-in system means the system is used in lamps and other appliances are parallelly connected so that each appliance is controlled individually.

Cleat Wiring consists of ordinary VIR or PVC insulated wires is compounded on walls and ceilings by means of porcelain cleats, wood, or plastic, temporary system and is not suitable for domestic usage. For example, used in an under-construction building.

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Answer:

d

Explanation:

Answer:

D

Explanation:

I t0ook the test and chose B and it was wrong and the answer was D.

Answer:

A thick grouping of nerves that runs down the back of the embryo

Explanation:

Answer:

B. Law of Conservation of Mass

Explanation:

In other words, the mass of any one element at the beginning of a reaction will equal the mass of that element at the end of the reaction. If we account for all reactants and products in a chemical reaction, the total mass will be the same at any point in time in any closed system.

Answer:

The rate of change of velocity of a moving body is called acceleration. mathematical formula of Acceleration = Final velocity-Initial velocity

________________________

Time taken

SI Unit of Acceleration is m/s2. If the Velocity of a moving body decreases, it's acceleration will be negative. Two examples of situations in which acceleration of the body is negative are ÷

Answer:

resultant force=16N→(TOWARDS THE DIRECTION OF 8N)

Explanation:

resultant force=8N+13N-5N

                        =16N→(TOWARDS THE DIRECTION OF 8N)

Answer:

.78 m/s north

Explanation:

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