Resistivity of metallic wire
depends on *

It's length
It's shape
It's thickness

Nature of material​

Answer:

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

Explanation:

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

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]

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

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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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: i think c

Explanation:QA: “What is ordinary glass made of ?”

Glass is mostly silica, or silicon dioxide, present as quartz in many types of sand. Pure silica forms a highly transparent glass, but has a very high melting or softening temperature, around 1700°C. Even at such high temperatures it is highly viscous and difficult to work. Its use is largely confined to applications requiring high transparency to ultra-violet and infra-red radiation, stability at elevated temperatures or low thermal expansion coefficient.

“Ordinary glass” windows and drinking vessels are typically made from soda-lime glass, containing silica with around 25% sodium, calcium and other oxides, which together reduce the softening temperature to roughly 500–600°C

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:

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:

False -> negative charge

Answer:

false

Explanation: electrons are negative charges

protons are positive charges

Answer:

good

Explanation:

Answer:

fine

Explanation:

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Answer:D.Keeping track of the exact amount of wind on each plant

Answer:

D. water

Explanation:

sugar ( glucose ) and oxygen are bi-products

Answer:

(d) water

Explanation:

water is required for photosynthesis to take place .

sugar , oxygen , ATP are not required to take place in photosynthesis.

Answer with Explanation:

Let me answer this in a simple way, since the density of stone is greater than that of water, the stone sinks as the weight of the stone is greater than the weight of water displaced by it. But the ship is designed in such a way that the relative density of the ship always becomes less than that of water. Therefore, the weight of the water displaced becomes equal to the total weight of the ship and thus it floats.

There are many other ways to explain this but this should give you the general idea.

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Explanation:

Magnetic lines of force are closed curves. C) Outside the magnet their direction is from north pole to south pole and inside the magnet these are from south to north pole.

Answer:

Don't Forget To Follow, Brainliest, And Give Me Heart :)

Answer:D

Explanation:

Answer:

w = 0.01 t⁻²   rad/h

Explanation:

Let's use trigonometry to find the elevation angle of the telescope, we assume that the rocket remains fixed in the telescope.

        tan θ = CO / CA

the adjacent leg is CA = 16 km = 16 10³ m

Let's use kinematics to find the height of the rocket

          v = y / t

          y = v t

this height is equal to the opposite leg

          CO = v t

we substitute

         tan θ = vt / 16

         tan θ = 1200/16 t

         tan θ = 75 t

         θ = tan⁻¹ ( 75 t )

speed is defined by

          w = dθ/dt

          w = [tex]\frac{1}{1 + (75 t)^2} \ 75[/tex]  

as time increases we can neglect the 1 of the denominator

          w = 1/75 t²

          w = 0.0133 t⁻²

Using three significant figures

           w = 0.01 t⁻²   rad/h

for this answer the time must be given in hours

Answer:

Because matter has been squeezed into a tiny space.

Explanation:

According to NASA, this can happen when a star is dying.

A black hole has no more gravity than the same amount of matter in any other form.

But remember that the gravitational forces are stronger as you get closer to the center of the body. The mass of a black hole is packed into such a small size (theoretically zero !) that you can get very close to its center. THAT'S where its gravity is hugely strong.

Answer:

The average velocity of an object is its total displacement divided by the total time taken. In other words, it is the rate at which an object changes its position from one place to another.

Explanation:

Average velocity is a vector quantity. The SI unit is meters per second. However, any distance unit per any time unit can be used when necessary, such as miles per hour (mph) or kilometer per hour (kmph)

Answer:

the ratio of total displacement by total time taken

i believe it would be Star A since Point A is a dwarf star and dwarf stars are usually most likely to have red coloring

Answer:

Star A

Explanation:

Literally the question has provided the answer itself

Calculation not required.

See the wordings

First star is dwarf star .

Dwarf star is mostly reddish brown or red colored .

Hence star A is the answer

Answer:

96 meters

Explanation:

d = st

d = (8 m/s)(12 s)

d = 96 m

Answer:

what do u need help with

Explanation:

Pа: 5. Mass of the earth is 6x10-kg and its radius is 6400km. What is the mass of a man weighting 977N? (99.99kg) ma. Orth be​.

Explanation:

p = F /A

F = P×A

F = 30,000 Pa / 0.1 m²

F = 300,000 N

Answer:

False.

Explanation:

A warm up is stretching in the beginning.

Answer:

0.25p.a

Explanation:

force=15N area=60m²

so pressure =force/area =15N/60m²=0.25p.a

Answer:

The resistance of a thin wire is greater than the resistance of a thick wire because a thin wire has fewer electrons to carry the current. The relationship between resistance and the area of the cross section of a wire is inversely proportional .

The best way to think about this is:

A thick/wide road, with many lanes, can carry more cars than a thin/narrow road, with only one or two lanes.

Answer:

the process of comparing unknown quantities with known standards quantities are known as measurement