what is meant by the statement that the linear expansivity of copper is 0.000017/k?
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oh, and uhmm;
steel bars each of length 3m at 29°c are to be used for constructing a rail line. if the linear expansivity of steel is 1.0×10⁻⁵/k. calculate the safety gap that must be kept between successive bars, if the highest temperature expected is 40°c

A muddy floor can be very slippery so if you jump on a muddy floor, you will most likely slip and hurt yourself.

A hard floor will most likely be dry. So when you jump on a hardwood floor, you are less likely to slip. But, you can hurt your knees if you're not careful.

Answer:

Injury can occur

Explanation:

you might be running then you start jumping without putting your heels down, then might get achilles tendonitis in your achilles tendons.

The exhaust temperature is 200 K

Explanation:

The maximum efficiency of a machine is given by the equation:

[tex]\eta=1-\frac{T_C}{T_H}[/tex]

where:

[tex]T_H[/tex] is the temperature of the hot reservoir

[tex]T_C[/tex] is the temperature of the cold reservoir

For the engine in this problem, we have:

[tex]\eta = 0.333[/tex] (efficiency is 33.3%)

[tex]T_H=300K[/tex] is the temperature of the hot reservoir

Re-arranging the equation for [tex]T_C[/tex], we can find the exhaust temperature (the temperature of the cold reservoir):

[tex]T_C=T_H(1-\eta)=(300)(1-0.333)=200 K[/tex]

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Answer:

200k

Explanation:

Answer:

The arc and flash burns results from high temperatures caused by an electric arc or explosion near the body

Explanation:

The arc and flash burn occurs due to high temperature because of electric arc or explosion near the body.  The basic reason for catching of fire is due to clothing. Because the fact the fabric catches fire more easily. For less damage the first thing one must follow is application of the antibiotic ointment as well as dressing soon. In severe cases it requires surgery. when electricity passes through our body causes burning very rapidly.

Final answer:

An electrical burn occurs when the skin is exposed to high temperatures from an electric arc or explosion, which can lead to serious complications, including dehydration, electrolyte imbalance, and infection. Immediate medical attention and treatment with IV fluids and nutrients are critical.

Explanation:

The type of burn described results from high temperatures caused by an electric arc or explosion near the body, which is often referred to as an electrical burn. These burns occur when the skin is damaged by intense heat from an electric source and can be extremely dangerous. They can be fatal due to the death of skin cells, leading to massive fluid loss, dehydration, electrolyte imbalance, and potential renal and circulatory failure.

Such burns require immediate medical treatment, which includes administering intravenous fluids to combat dehydration and providing intravenous nutrients to help the body repair tissues and replace lost proteins. Moreover, electrical burns increase the risk of infection as the damaged skin is more vulnerable to bacteria and pathogens.

-- A horizontal line on a position/time graph says that as time goes on, the position isn't changing.  The object is standing still. At rest. Motionless.

-- A horizontal line on a speed/time graph says that as time goes on, the speed isn't changing.  If that doesn't happen to be zero, then the object is moving at a constant speed, and its position keeps changing at constant rate.  On a position/time graph, this same motion would be a straight line slanting  upward.

Final answer:

A horizontal line on a position vs. time graph indicates an object at rest, while a horizontal line on a speed vs. time graph shows an object moving at a constant speed.

Explanation:

Graphs play an essential role in analyzing motion in physics. The representation of motion on position vs. time graphs and speed vs. time graphs can tell us a lot about the behavior of moving objects.

When examining a position vs. time graph, a horizontal line indicates that the position of an object does not change as time passes, which means the object is stationary or at rest. There is no change in position, so the velocity is zero. On the other hand, a horizontal line on a speed vs. time graph suggests that the object is moving at a constant speed. The flat line indicates that the speed does not change over time; the object is not accelerating or decelerating.

To sum up, a horizontal line on a position graph signifies no movement (zero velocity), while a horizontal line on a speed graph indicates constant movement (constant speed).

Final answer:

A horizontal line on a position vs. time graph indicates an object at rest, while a horizontal line on a speed vs. time graph shows an object moving at a constant speed.

Explanation:

Graphs play an essential role in analyzing motion in physics. The representation of motion on position vs. time graphs and speed vs. time graphs can tell us a lot about the behavior of moving objects.

When examining a position vs. time graph, a horizontal line indicates that the position of an object does not change as time passes, which means the object is stationary or at rest. There is no change in position, so the velocity is zero. On the other hand, a horizontal line on a speed vs. time graph suggests that the object is moving at a constant speed. The flat line indicates that the speed does not change over time; the object is not accelerating or decelerating.

To sum up, a horizontal line on a position graph signifies no movement (zero velocity), while a horizontal line on a speed graph indicates constant movement (constant speed).

Answer:

an average of 92,955,807 miles

Explanation:

Answer:

First I should say that the Earth's orbit around the Sun is elliptical, not perfectly circular, so the Earth-Sun distance is changing as we speak just from the Earth traveling in its orbit around the Sun. There are some long-period oscillations, but those are very small, and don't imply that we're systematically moving towards or away from the Sun.

I hope this answer helps you :)

The other material would be needed for a student to construct a basic electric motor is a magnet.

Answer: Option A

Explanation:

For constructing fundamental electric motors coils of wire, the battery, few paper clips, a thermometer, and a magnet are mandatory. The principle on which it works is when in magnetic field rectangular coil placed and current passes than force will act on it and rotate it continuously to convert electrical energy into mechanical energy.

Here magnet is compulsory to generate motion when two bar magnets placed against the north and south pole of each other than attractive force but if placed in a similar direction than repulsive force occur. Therefore, these attractive and opposing forces generate rotational motion.

Answer:

The answer is A

Explanation:This is the answer

When someone uses his thumb to push a pin into a block of wood the pressure on the wood is greater than the pressure on this thumb​ because the area of the pin on the thumb side is larger than the area of the pin on the wood side

The total applied force per unit of area is known as the pressure.

The pressure depends both on externally applied force as well the area on which it is applied.

The mathematical expression for the pressure

Pressure = Force /Area

the pressure is expressed by the unit pascal or N /m²

Since, the area of the pin on the thumb side is larger than the area of the pin on the wood side, when someone uses his thumb to push a pin into a block of wood, the pressure on the wood is greater than the pressure on this thumb.

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Natural selection is the process of organisms adapting to their environments over time.

Explanation:

Natural selection refers the process to various survival and multiplication of organisms due to environmental properties. For example peacock, pepper moth, etc. These lead to evolutionary changes in which individual with specific traits has higher survival or reproduction than individuals in other populations and passes on these hereditary genetic traits to their offspring.

A process in which organisms are well suited to the surroundings than others generate more offspring. Due to this process, the percentage of organisms that adapt to the environment is increasing with each generation.

Answer:

The force acting on the free-falling object is, F = 1.47 N

Explanation:

Given data,

The mass of the object, m = 150 g

When an object is under free-fall, the only force acting on the object is the gravitation force neglecting the air resistance.

So, when an object is close to the surface of the earth acceleration due to gravity acting on the object is equal to g.

The value of g at the surface of the Earth is, g = 9.8 m/s²

Therefore, the force acting on the object under free fall is,

                                                          F = mg

                                                              = 0.15 x 9.8

                                                               = 1.47 N

Hence, the force acting on the free-falling object is, F = 1.47 N

Answer:  

The first graph is the trend line.

Explanation:

Trend Line

It's a line indicating the tendency of something being measured or evaluated. The trend line is meant to represent an approximation of a set of points of a measured magnitude.  

We have three possible 'trend lines' to choose from. The second is not a line, so it's not the correct option. The third is not a line either, it's just a graph who joins all the measured points. It doesn't mark a trend.

The first graph is a trend line because it's a single line and can be used to represent the whole set of values  .

Answer:

the Answer is A

Explanation:

because the swinging motion of a pendulum is due to the force of gravity generated by the earth's size

the question is correct

Final answer:

The law of conservation of mechanical energy states that the total mechanical energy (kinetic plus potential) in a closed system subjected to conservative forces remains constant, assuming no energy is lost via non-conservative forces like friction.

Explanation:

Law of Conservation of Mechanical Energy

The law of conservation of mechanical energy states that in a closed system where only conservative forces are acting, and in the absence of non-conservative forces such as friction or air resistance, the total mechanical energy of the system remains constant. Mechanical energy is the sum of the object's kinetic energy (energy due to motion) and potential energy (energy stored due to position). This implies that any loss in potential energy will result in an equal increase in kinetic energy, and vice versa, hence keeping the total energy unchanged.

As an example, consider a roller coaster. At the highest point, the car has maximum potential energy and minimum kinetic energy. As the car descends, potential energy decreases while kinetic energy increases. If we assume no energy loss to friction, the sum of potential and kinetic energies at any point will equal the total mechanical energy at the top of the first rise, illustrating the conservation of mechanical energy.

In mathematical terms, the law can be expressed as K + U = constant, where K represents kinetic energy and U represents potential energy. This conservation is also a consequence of the work-energy theorem when applied to conservative forces, leading to the understanding that the net work done is equal to the change in kinetic energy of the system.

The moon is not seen at all on the new moon because:

The moon itself doesn't make a light, it reflects sunlight. At the point when the moon lies between the Earth and the Sun, it is just the posterior of the moon that is light by the Sun. In this circumstance, the side of the moon confronting the Earth can't mirror any light whatsoever and seems dull.  

The distinction between another moon and a sunlight based over-shadowing is during a sun oriented obscuration, the moon is actually in the position to completely obstruct the sun during the day.

Answer:

-$1,000

Explanation:

$3000 - $4000

Answer:

-1000

3000-4000=-1000

The force of attraction between the opposite charges of the ions in an ionic compound is an ionic bond.

Explanation:

The transfer process of valence electron between atoms referred as ionic bond. This is a kind of chemical bonds which can create two oppositely charged ions. In the presence of ionic bonds, the metal loses electrons and becomes a positive charge cation, while non-metal accepts these electrons and becomes a negative charge anion.

Here, more than 1 electron can be emitted or received to meet the octet principle and the net charge of the compound should be zero. For example: Table salt. In this compound, sodium loses the electron to become [tex]N a^{+}[/tex], while the chlorine loses the electron to become [tex]c l^{-}[/tex].

The force of attraction between opposite charges of ions in an ionic compound is caused by electrostatic forces, forming what is known as an ionic bond. This creates stability in the compound and the strength of this attraction is measured by the lattice energy. While ionic compounds are generally poor electrical conductors in their solid state, they can become excellent conductors when dissolved or melted.

The force of attraction between the opposite charges of the ions in an ionic compound, often referred to as an ionic bond, is a result of electrostatic forces. For instance, in sodium chloride or table salt, positively charged sodium ions bond with negatively charged chloride ions, forming a crystalline molecule with exception of any net charge. That's because of the attraction between the oppositely charged ions which keeps them in close proximity.

An ionic compound is stable due to this electrostatic attraction between its positive and negative ions. An important concept in this context is lattice energy: it's the energy required to separate a mole of a solid ionic compound into its gaseous ions, and is essentially a measure of the strength of the ionic bonds in the compound.

Ionic compounds, or salts, tend to be rigid and brittle, having high melting and boiling points - all indications of the strength of ionic bonds. They are poor conductors of electricity in solid state as the strength of these bonds prevents ions from moving freely, however, once dissolved or melted, ionic compounds turn into excellent conductors because the ions can now move freely.

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Answer:

500 nm

Explanation:

[tex]\lambda = c/\nu = \frac{3*10^8}{6*10^{18}} = 5*10^{-11}[/tex] m

Answer:

5*10^-11

Explanation:

From alvs

The ratio between power of A and power of B is 2

Explanation:

In physics, power is defined as the ratio between the work done and the time taken to do the work:

[tex]P=\frac{W}{t}[/tex]

where

P is the work done

t is the time taken

In this problem, we have:

Person A and person B do the same amount of work --> let's call this work W

Person A does this work in a time of [tex]t_A = 1 s[/tex], so the power delivered by A is

[tex]P_A = \frac{W}{1}=W[/tex]

Person B does this work in a time of [tex]t_B = 2 s[/tex], so the power delivered by B is

[tex]P_B = \frac{W}{2}[/tex]

So, the ratio of the powers delivered by the two persons is

[tex]\frac{P_A}{P_B}=\frac{W}{W/2}=2[/tex]

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1) The new gravitational force is half of the original force

2) The new gravitational force is 1/8 of the original force

Explanation:

1)

Let's call F the initial gravitational force between the object A and B. The magnitude of F is given by the equation

The magnitude of the gravitational force between two objects is given by

[tex]F=G\frac{m_A m_B}{R^2}[/tex]

where

[tex]G=6.67\cdot 10^{-11} m^3 kg^{-1}s^{-2}[/tex] is the gravitational constant

[tex]m_A,m_B[/tex] are the masses of the two objects

R is the separation between them

In this part of the problem, we are told that the distance between the two objects doubles, so the new distance is

R' = 2R

While the mass of object A is doubled, so the new mass is

[tex]m_A' = 2m_A[/tex]

Therefore, the new gravitational force is

[tex]F' = \frac{Gm_A' m_B}{R'^2}= \frac{G(2m_A) m_B}{(2R)^2}=\frac{1}{2}(\frac{Gm_A m_B}{R^2})=\frac{F}{2}[/tex]

Therefore, the new force is half of the original force.

2)

In this second part of the problem, the distance between the two objects doubles, so the new distance is

R' = 2R

While the mass of object A is halved, so the new mass is

[tex]m_A' = \frac{m_A}{2}[/tex]

Therefore, the new gravitational force this time is:

[tex]F' = \frac{Gm_A' m_B}{R'^2}= \frac{G(m_A/2) m_B}{(2R)^2}=\frac{1}{8}(\frac{Gm_A m_B}{R^2})=\frac{F}{8}[/tex]

Therefore, the new force is 1/8 of the original force.

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Explanation:

For projectile motion, use constant acceleration equation:

Δx = v₀ t + ½ at²

where Δx is the displacement,

v₀ is the initial velocity,

a is the acceleration,

and t is time.

Both objects are projected upward with velocity u.  The second object is thrown after a time t₀.

For the first object:

Δx = u t + ½ (-g) t²

Δx = u t − ½g t²

For the second object:

Δx = u (t−t₀) + ½ (-g) (t−t₀)²

Δx = u (t−t₀) − ½g (t−t₀)²

Assuming the objects meet, the displacements will be equal:

u t − ½g t² = u (t−t₀) − ½g (t−t₀)²

u t − ½g t² = u (t−t₀) − ½g (t² − 2tt₀ + t₀²)

u t − ½g t² = u t − u t₀ − ½g t² + g tt₀ − ½g t₀²

0 = -u t₀ + g tt₀ − ½g t₀²

0 = -u + g t − ½g t₀

g t = u + ½g t₀

t = u/g + t₀/2

Answer:

A)

B)

Values of the domain that make sense would be those from 0 on because there are no negative number of sessions; values of range that make sense would be also those from 0 on because there are no negative number of pictures.

C)

[tex]f(x)=15x[/tex], where "x" is the number of sessions.

If we have 22 session then:

[tex]f(22)=15*22[/tex]; f(22)=[tex]f(22)=330[/tex]

Explanation:

Answer:

I = 24 A

Explanation:

This is Parallel Circuit and it is the first principle of parallel circuit that voltage will be equal in all components in the circuit

It includes 10 resistors Therefore the voltage across,

R1 = R2 = R3 = R4 = R5 = R6 = R7 = R8 = R9 = R10 = voltage in battery

We will apply Ohm's Law to each resistor to find its current because we know the voltage across each resistor is 12 V  and the resistance of each resistor is 5Ω

I (R1) = E (R1) / R1

I (R1) = 12v / 5Ω

I (R1) = 2.4 A

The value resistance E of all resistors are same therefore by applying the formula above the value of current in all resistors will be 2.4 A

The Total current in the circuit will be

I (total) = I (1) + I (2) + I (3) + I (4) + I (5) + I (6) + I (7) + I (8) + I (9) + I (10)

I (total) = 2.4 + 2.4 + 2.4 + 2.4 + 2.4 + 2.4 + 2.4 + 2.4 + 2.4 + 2.4

I (total) = 24 A

Answer:

Alternating current

Explanation:

The electrical current periodically changes direction.

Answer:

alternating current

Explanation:

A stands for alternating

C stands for current

the current which changes direction ( several times per second ) is known as AC or alternating current

Answer:

39)

a) distance traveled = 1 mile

b) displacement = 0 mile

40)  - 4 (m/s)

41-) distance traveled = 5 [m]

displacement = 3.6 [m]

Explanation:

The distance differs from the displacement, the distance traveled is equal to the sum of all displacements made by the particle or object.

Displacement is the difference between the initial point and the final point where the object or particle was stopped.

Then we can use the equation given:

[tex]a=\frac{(v_{f} - v_{i} )}{t} \\where:\\v_{f}=16[m/s]\\v_{i}=2[m/s]\\t=3.5[s]\\a=\frac{(2-16)}{3.5}\\ a=-4[m/s][/tex]

The minus sign means the particle is slowing down.

For the 41) we can see the attached image.

In the graph we can see that the particle moves north 3 miles, so that the first distance is 3 miles, then moves 2 miles east being the second distance of 2 miles. Thus the sum of the distances is 3 + 2 = 5 miles.

Displacement is the difference between the endpoint and the initial point since the form of displacement is a straight line, we can use the formula of the straight line or the theorem of Pythagoras.

[tex]d=\sqrt{(2-0)^{2}+(3-0)^{2}  }\\d=3.6 [mi][/tex]

Ocean Currents is the factor that determines the air temperature in coastal regions having same latitude.

Explanation:

There are factors that use to determine air temperature. They are latitude, altitude, region, water current, etc and it is based on the combination of water, air, and land.

If two coastal regions situated in the same latitude means they are not in the same region. Another city can be in the same latitude but in longitude. All the coastal regions don't have the same air temperature.

The air temperature in coastal regions can measured by the Ocean Current. A hypothesis of using cold water and warm water use to determine the air temperature.

Answer:

That would be Spring C

Explanation:

i took the test :P

Answer:

The answer is C please give me brainliest

Explanation:

The law of floatation states that, a floating body displaces its own weight of the fluid in which it floats.

Answer: what comes to mind when we hear the word "Friction" ?

Basically friction is a "Force" that opposes an intend(ing) motion.

Explanation:

By motion I mean movement.

By force I mean a body that carries with it energy.

So to understand this better, just see it as a force(thing) that prevents or stops you from taking action.

Answer:

Chimps and apes are still here because humans did not evolve from all apes and chimps.

Explanation: