12,000 scientific notation

C is the correct answer but the best possible answer is that work is done when a force is imposed on an object and the object moves in the same direction as the force

Hope this helps!

Work in physics is done when a force is applied and causes displacement in the direction of the force. The correct answer is that for work to be done, a force must be transferred and the object must move.

In physics, work is defined as the transfer of energy to an object by applying a force that causes the object to move.

The correct answer to what determines whether work is being done is C: In order for work to be done a force must be transferred and the object must move.

For work, in the scientific sense, to occur, a force must be exerted and there must be displacement in the direction of the force.

Formally, the work done is the product of the component of the force in the direction of the displacement and the distance through which the force acts, which is articulated in the equation W = | F | (cosθ) | d |, where W is work, F is the magnitude of the force, cosθ is the cosine of the angle between the force vector and the displacement vector, and d is the displacement.

Answer:

Electric current is the flow of a charge

Explanation:

Electric current is defined as the flow of electric charges. Mathematically, it is given by :

[tex]I=\dfrac{q}{t}[/tex]

Where

q = electric charge

t = time interval

The SI unit of electric current is ampere. It is denoted by letter A. According to Ohm's law, electric current can be given by  voltage divided by resistance of the circuit. Hence, the correct option is (c) " Electric current is the flow of a charge ".                      

Explanation:

Given that,

Acceleration of the treadmill, [tex]a=4.7\times 10^{-3}\ m/s^2[/tex]

Time, t = 5 min = 300 s

Acceleration is given by :

[tex]a=\dfrac{v-u}{t}[/tex]

(a) (v-u) is the change in speed.

[tex]v-u=a\times t[/tex]

[tex]v-u=4.7\times 10^{-3}\times 300[/tex]  

[tex]v-u=1.41\ m/s[/tex]

So, the change in speed of the treadmill is 1.41 m/s.      

(b) Initial speed of the treadmill, u = 1.7 m/s

The final speed is given by using equation as :

[tex]v=u+at[/tex]

[tex]v=1.7+4.7\times 10^{-3}\times 300[/tex]

v = 3.11 m/s

Hence, this is the required solution.

Correct answer choice for question 1 is :

C) Iron magnet

Explanation:

Materials which will be magnetic , that are also those that are powerfully drawn to a magnet, as known as magnetism. These embrace iron, nickel, cobalt, some alloys of rare-earth metals, and a few present minerals like static magnet. Magnets attract iron thanks to the influence of their magnetic flux upon the iron. once exposed to the magnetic flux, the atoms begin to align their electrons with the flow of the magnetic flux, that makes the iron magnetic likewise. This, in turn, creates an attraction between the 2 magnetic objects.

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Correct answer choice for question 7 is :

D) Domains

Explanation:

Magnetism could be a category of physical phenomena that are mediate by magnetic fields. Electrical currents and therefore the magnetic moments of elementary particles bring about to a magnetic flux, that acts on alternative currents and magnetic moments. Iron filings interested in a horseshoe magnet show the magnetic flux. Magnetism is one side of the combined magnetic force force. It refers to physical phenomena arising from the force caused by magnets, objects that turn out fields that attract or repel alternative objects.

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Correct answer choice for question 8 :

D) Domains

Explanation:

Magnetism could be a category of physical phenomena that are mediate by magnetic fields. Electrical currents and therefore the magnetic moments of elementary particles bring about to a magnetic flux, that acts on alternative currents and magnetic moments. Iron filings interested in a horseshoe magnet show the magnetic flux. Magnetism is one side of the combined magnetic force force. It refers to physical phenomena arising from the force caused by magnets, objects that turn out fields that attract or repel alternative objects.

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Answer:

392.8 m

Explanation:

Horizontal velocity is 38.89 m/s

Vertical distance y =0.5 km = 500 m

First calculate the time in which the package will hit the ground.

Use the second equation of motion

[tex]y = u t + 0.5 at^2[/tex]

[tex]500 = 0 + 0.5 (9.8) t^2[/tex]

t =10.1 s

Horizontal distance covered in the same time is

x = ut = (38.89) (10.1) = 392.8 m

The plane will cover the same horizontal distance in the time in which the package hits the ground.

If the number of loops in a coil of wire is increased on an electromagnet, the magnetic field strength of the coil will increase.

An electromagnet is a type of magnet that generates a magnetic field by using an electric current. Electromagnets are typically made of wire twisted into a coil. A current flowing through the wire produces a magnetic field that is concentrated in the coil's central hole.

When the current is switched off, the magnetic field vanishes. The wire turns are frequently wound around a magnetic core consisting of a ferromagnetic or ferrimagnetic material, such as iron; the magnetic core concentrates the magnetic flux, resulting in a stronger magnet.

As the current grows, so does the strength of the magnetic field. The coil's number of turns grows. An iron core creates a powerful electromagnet that is easily magnetized and demagnetized.

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We cannot estimate the blood's acceleration during the speeding up phase without knowing the time taken.

The student wants to estimate the blood's acceleration during the speeding up phase of its motion. To solve this, we can use the equation for acceleration:

a = (v - u) / t

where a is the acceleration, v is the final velocity, u is the initial velocity, and t is the time taken. In this case, the blood is accelerated from rest (0 cm/s) to 30.0 cm/s in a distance of 1.80 cm. To calculate the time (t), we can rearrange the equation to:

t = (v - u) / a

Substituting the values, we have:

t = (30.0 cm/s - 0 cm/s) / a

To find a, we need to know the value of t. Unfortunately, the value of t is not given in the question, so we cannot determine the blood's acceleration during the speeding up phase without knowing the time taken. Therefore, we cannot provide an estimate for the blood's acceleration in this case.

Answer:

Hydro energy

Explanation:

Answer:

hydro energy would be the answer.

Explanation:

In a water molecule, oxygen has the greatest electronegativity, leading to the polar nature of water and its ability to form hydrogen bonds.

Because oxygen has an electronegativity of 3.44 compared to hydrogen's 2.20, it attracts the shared electrons in the molecule more strongly than the hydrogen atoms do. Consequently, the shared electrons spend more time near the oxygen atom, resulting in a higher electron density around it and making the oxygen end of the water molecule slightly negative. This imbalance in electron density is significant, as it contributes to the molecular polarity of water, where hydrogen atoms acquire a partial positive charge and oxygen atoms a partial negative charge. The high electronegativity of oxygen relative to hydrogen in water molecules leads to its well-known polar properties and its ability to form hydrogen bonds.

In physics, a vector is a quantity that has both magnitude and direction. It can be represented by an arrow and is used to describe physical quantities such as displacement, velocity, force, and electric and magnetic fields.

In physics, a vector is a quantity that has both magnitude and direction. It can be represented by an arrow, where the length of the arrow represents the magnitude and the direction of the arrow represents the direction. Vectors are used to describe physical quantities such as displacement, velocity, force, and electric and magnetic fields.

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The strength of an ionic bond is best represented by lattice energy, which measures the energy required to separate one mole of a compound into gas phase ions. Factors that affect lattice energy include the magnitude of ionic charges and the size of the ions. Higher lattice energy indicates stronger ionic bonds.

The type of energy that best represents the strength of an ionic bond is known as lattice energy. Lattice energy is the energy required to separate one mole of a compound into its gas phase ions. This energy measurement is crucial because it reflects the strength of the electrostatic attraction between the ions in an ionic compound. The stronger this attraction, the greater the lattice energy, indicating a stronger ionic bond. Factors influencing lattice energy include the magnitude of the ionic charges and the size of the ions; higher charges and smaller ion sizes contribute to stronger ionic bonds due to closer ion proximity and stronger electrostatic forces.

Lattice energies are often calculated using the Born-Haber cycle, a process that accounts for all energetic steps in converting elements into an ionic compound. Higher lattice energy corresponds to stronger ionic bonds, which directly impacts the compound's physical properties, such as its melting point. For instance, a compound with high lattice energy will have a high melting point, affirming the strong ionic bonds holding the compound together.

A sled is pushed along an ice-covered lake. It has some initial velocity before coming to rest in 15m. It took 23 seconds before the sled and rider came to a rest. If the rider and sled have a combined mass of 52.5 kg, the magnitude, and direction of the force - 2.98 N which is called friction.

Given:

Time t = 15 s

distance d = 23 m

mass = 52.5

As we know the formula,

[tex]Solution:\\\\\\bar v = \frac{d}{t}\\\\ = \frac{15}{23}\\ \\ = 0.65 \ m/s\\\\According\ to\ the\ question,\\v_f =0\\then,\\2 \bar v = v_i\\2(0.65)=v_i\\v_i=1.3 \ m/s\\u = Initial\ velocity,\\v = Final\ Velocity,\\a = acceleration\\\\According\ to\ the\ second\ law\ of\ motion\\Force = m\times a\\ = (-.057)\times 52.5\\ = -2.97 \ N[/tex]

Thus, F is taken to be negative. So, the stopping force is -2.97 N and this force is the frictional force and its direction is opposite to that of motion.

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Explanation:

A free body diagram shows all the forces acting on the object- all the magnitudes and the directions. The forces acting at an angle on an object are written in the form of their components in the horizontal and vertical direction.  The forces in the single direction are added up. Thus, a free body diagram shows the net force acting on an object.

Final answer:

Instantaneous speed and instantaneous velocity are related but different concepts in physics. The instantaneous speed refers to the speed of an object at a specific instant in time, while instantaneous velocity includes both magnitude and direction. If the instantaneous speed of an object remains constant, its instantaneous velocity can change if there is a change in direction of motion. Similarly, if the instantaneous velocity remains constant, the instantaneous speed can change if the object accelerates or decelerates.

Explanation:

Instantaneous speed and instantaneous velocity are related but different concepts. Instantaneous speed refers to the speed of an object at a specific instant in time, while instantaneous velocity refers to the velocity of an object at a specific instant in time, including both magnitude and direction. Although the instantaneous speed of an object can remain constant, its instantaneous velocity can change if there is a change in direction of motion. For example, if an object is moving in a circular path at a constant speed, its instantaneous speed remains the same, but its instantaneous velocity constantly changes because the direction of motion is constantly changing.

Similarly, if the instantaneous velocity of an object remains constant, its instantaneous speed can still change if the object speeds up or slows down. This can occur when an object experiences an acceleration or deceleration. For example, if a car is moving at a constant velocity of 50 km/h and suddenly accelerates, its instantaneous velocity remains constant but its instantaneous speed increases.

The box will travel 4.17 meters with a given coefficient of kinetic friction of 0.15 and with an initial speed of 3.5 m/s.

It is known as a force that acts between moving surfaces as kinetic friction. A force acting in the opposite direction of the movement of a body on the surface is felt. The coefficient of kinetic friction between the two materials will determine the size of the force.

It is simple to define friction as the force stopping a sliding item. Everything has kinetic friction, which impedes the motion of two or more objects. When an object desires to slide in one direction, the force acts in the opposing direction.

According to the question, the given values are :

Coefficient of kinetic friction, [tex]\mu[/tex] = 0.15

Initial speed, V(i) = 3.5 m/s

Final speed, V(f) = 0 m/s

F = ma and,

[tex]F_r[/tex] = ma

[tex]\mu F_r[/tex] = ma

[tex]\mu[/tex]g = a

a = 0.15 / 9.8

a = 1.47 m/s².

V²(f) = V²(i) + 2ad

d = [V²(f)- V²(i)] / 2a

d = 0 -(3.5)² / 2(-1.47)

d = 4.17 m

Hence, the box with travel 4.17 meters.

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Answer:

Absolute Zero

Explanation:

The lowest limit of thermodynamic temperature is called as absolute zero. By international agreement, on kelvin scale it is 0 K and on Celsius scale it is equal to -273.15° C. This is considered as the lowest possible temperature. At this temperature the particle vibration is minimum and no heat energy remain in the substance.

Answer:

r = [3 * (pAl/MAl)]/(4 * pi)]^1/3

r = [3 * (pFe / MFe)]/(4 * pi)]^1/3

Explanation:

In the equilibrium state, aluminum and iron have the same mass. From the density equation and solving for the mass we have:

Mass = density/volume

MFe = pFe/V

MAl = pAl/V

In equilibrium, we have that MFe = MAl

Solving for the volume:

MFe = pFe/V

V = pFe/MFe

MAl = pAl/V

V = pAl/MAl

The equation for the volume of a sphere is equal to:

V = (4 * pi * r^3)/3

Replacing the volume of both iron and aluminum, we have:

V = (4 * pi * r^3)/3

r = [(3 * V)/(4 * pi)]^1/3

r = [3 * (pAl/MAl)]/(4 * pi)]^1/3

r = [3 * (pFe/MFe)]/(4 * pi)]^1/3

Final answer:

The skater's velocity at his lowest point, where all his potential energy has been converted to kinetic energy, is approximately 3.96 m/s given his initial height of 8.0 meters and mass of 75 kg.

Explanation:

The question you're asking involves the principles of conservation of energy, particularly how potential energy is converted into kinetic energy. Since the skater starts at a height of 8.0 meters and ends at a height of 0 meters, all of the potential energy due to gravity would be converted to kinetic energy (assuming no air resistance and a frictionless surface). The potential energy at the start (PEstart) equals the kinetic energy at the lowest point (KElowest).

To find the velocity of the skater at the lowest point, we use the formula for gravitational potential energy (PE = mgh) and set it equal to the formula for kinetic energy ½ mv2, where 'm' is mass, 'g' is the acceleration due to gravity (9.81 m/s2), 'h' is the initial height, and 'v' is the velocity.

So, PEstart = mgh = KElowest = ½ mv2. Plugging in the values, we get 75 kg × 9.81 m/s2 × 8.0 m = ½ × 75 kg × v2. Solving for 'v', the velocity of the skater at his lowest point, we find that:

(75 kg × 9.81 m/s2 × 8.0 m) / (0.5 × 75 kg) = v2
(588.6 kg*m2/s2) / (37.5 kg) = v2
15.7 m2/s2 = v2
v = √(15.7 m2/s2)
v ≈ 3.96 m/s

Therefore, the skater's velocity at his lowest point is approximately 3.96 m/s.

The initial velocity of the skydiver is 0 ft/s. After 5 seconds, the velocity is approximately 34.5 ft/s. After 15 seconds, the velocity is approximately 60.2 ft/s.

(a) To find the initial velocity of the skydiver, we need to evaluate v(t) at t = 0. Substitute t = 0 into the equation v(t) = A(1 − e^-kt) . Plugging in A = 64 and k = 0.19, we get v(0) = 64(1 - e^0) = 64(1 - 1) = 0 ft/s.

(b) To find the velocity after 5 seconds, substitute t = 5 into the equation. v(5) = 64(1 - e^(-0.19 * 5)) = 64(1 - e^(-0.95)) ≈ 34.5 ft/s .

To find the velocity after 15 seconds, substitute t = 15 into the equation. v(15) = 64(1 - e^(-0.19 * 15)) = 64(1 - e^(-2.85)) ≈ 60.2 ft/s .

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The initial velocity of the skydiver is 0 ft/s. After 5 seconds, the velocity is approximately 39.2 ft/s, and after 15 seconds, it is approximately 60.3 ft/s.

Let's solve the problem about the skydiver's velocity over time. The velocity function given is [tex]v(t) = A(1 - e^{-kt})[/tex] where A = 64 ft/s and k = 0.19 s⁻¹.

(a) Initial Velocity

The initial velocity of the skydiver occurs at t = 0. Plugging t = 0 into the velocity equation:

[tex]v(0) = 64(1 - e^{-0.19*0})[/tex]

Since e0 = 1:

v(0) = 64(1 − 1) = 0 ft/s

Therefore, the initial velocity of the skydiver is 0 ft/s.

(b) Velocity after 5 s and 15 s

Let's find the velocity after 5 seconds (t = 5):

[tex]v(5) = 64(1 - e^{-0.19*5})[/tex]

Calculating the exponent:

e-0.95 ≈ 0.387

So:

v(5) = 64(1 − 0.387) = 64(0.613) ≈ 39.2 ft/s

Now, let's find the velocity after 15 seconds (t = 15):

[tex]v(15) = 64(1 - e^{-0.19*15})[/tex]

Calculating the exponent:

e-2.85 ≈ 0.058

So:

v(15) = 64(1 − 0.058) = 64(0.942) ≈ 60.3 ft/s

Therefore, the velocities after 5 and 15 seconds are approximately 39.2 ft/s and 60.3 ft/s, respectively.

To describe velocity, you need to know speed and direction. Option (a) is correct.

You need to understand direction and speed in order to define velocity. The magnitude (speed) and direction of an object's motion are both included in the vector variable known as velocity. An object's speed is represented by the speed component and its direction by the direction component. Therefore, both speed and direction must be taken into account in order to adequately represent velocity.

Speed (how quickly an object is traveling) and direction (the path it is taking) are two essential components of velocity. These two elements work together to provide a precise description of an object's velocity.

Hence, To describe velocity, you need to know speed and direction. Option (a) is correct.

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The greater the force exerted by the engine of a car over a set distance, the greater the change in  momentum.

The definition of force in physics is: The push or pull on a massed object changes its velocity.

An external force is an agent that has the power to alter the resting or moving condition of a body. It has a direction and a magnitude. A spring balance can be used to calculate the Force. Newton is the SI unit of force.

According to Newton's second law of motion:

Force = rate of change in momentum per unit time.

Hence, The magnitude of the change in momentum increases with the amount of force applied by a car's engine over a given distance.

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Answer:

Explanation: B. A change in particle position

Answer: Option (B) is the correct answer.

Explanation:

Melting point is defined as the point at which a solid substance changes into liquid state.

During the melting point temperature of substance remains constant until the whole solid substance changes into liquid state.

At the melting point, particles of the solid vibrate rapidly and as a result position of the particles changes from one place to another.

Thus, we can conclude that as a solid reaches its melting point intermolecular bonds have been disrupted, causing a change in particle position.