Howard i moving a 90 kg wooden crate from one ide of hi office to the other. To accomplih thi, he tie a rope around hi wait and begin to walk, o that the crate i dragged horizontally acro the floor. If the coefficient of friction between the crate and the floor i 0. 159, what force mut Howard apply to to the rope to move at a contant peed?

A train locomotive pull a train with a mass of 1. 30 ✕ 107 kg on level rail. The locomotive exert a constant force of 6. 90 ✕ 105 N on the train. 244.5 minutes time does it take to increase the speed of the train from rest to 78. 0 km/h.

The time it takes to increase the speed of the train from rest to 78.0 km/h, you need to use the equation for acceleration:

= a

= F / m

where a is the acceleration of the train, F is the force exerted on the train by the locomotive, and m is the mass of the train.

Putting the values from the problem gives:

a = (6.90 x 10^5 N) / (1.30 x 10^7 kg)

= 5.31 m/s^2

To find the time it takes to increase the speed of the train from rest to 78.0 km/h, you can use the equation:

v = v0 + at

where v is the final speed of the train, v0 is the initial speed of the train (which is 0 in this case), a is the acceleration of the train, and t is the time.

Putting the values from the problem and solving for t gives:

= t

= (78000 m/h - 0 m/s) / (5.31 m/s^2)

= 14670 s

Since there are 60 seconds in a minute, the time it takes to increase the speed of the train from rest to 78.0 km/h is approximately 14670 s / 60 s/min = 244.5 minutes.

Therefore, the correct answer is "244.5".

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The density of the sphere given it stretches the spring 8 cm from it's equilibrium position is 1.25 g/cm³

First, we shall obtain the mass of the sphere. Details below:

F = mg

F = Ke

Thus,

mg = Ke

Divide both sides by g

m = Ke / g

m = (80 × 0.08) / 9.8

m = 0.653 Kg

Multiply by 1000 to express in grams

m = 0.653 × 1000

m = 653 g

Finall, we shall determine the density of the sphere. Details below:

Density = mass / volume

Density of sphere = 653 / 523

Density of sphere = 1.25 g/cm³

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The statement 'the system does work on surroundings' is false because the work done is a positive quantity.

This question can be answered using the first law of thermodynamics.

The First Law of Thermodynamics is a thermodynamic adaptation of the law of conservation of energy. "The overall energy in a system remains constant, even when it may be transformed from one form to another," says one basic expression. Another typical phrase is "energy cannot be generated or destroyed" (in a "closed system"). While there are other nuances and consequences that may be better conveyed in more sophisticated formulations, this is the fundamental premise of the First Law.

According to first law,

U= Q+W

U: internal energy of the system

Q: amount of heat

W: work done

Q= -17 kJ, W= 21 kJ

If Q is positive it means heat flows into the system. If Q is negative it means heat flows out of the system.

In the given question heat s negative which means heat flows into the system.

Work done is positive hence work is done on the system.

U= Q+W

U= -17+21= 4kJ

This is an exothermic process since Q is negative.

Complete question:

For a particular process q = –17 kj and w = 21 kj. Which of the following statements is false?

a) heat flows from the system to the surrounding

b) the system does works on the surrounding

c) U= +4kJ

d) the process is exothermic

e) none of the above is false

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The other classes of stars besides those in the primary obafgkm sequence are spectral types L, T, and Y.  They significantly different from their more massive peers.

Stars are substantial gas spheres. The star's core is compressed by the force of gravity, which raises its temperature to almost 10 million Kelvin. Nuclear fusion can commence at these temperatures and densities. When four hydrogen atoms unite to make a single helium atom, energy is released. The starlight comes from this.  More massive stars have hotter cores, which fuse hydrogen more quickly. They emit more light and heat than the Sun. The Sun has enough hydrogen to last for roughly 10 billion years; larger stars burn away more quickly. According to their spectra, astronomers categorize stars. Given that stars are, roughly speaking, black things, the hotter stars are blue and the colder stars are red.

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The force of gravity between the two asteroids will be 125 *10^6 n

From the data,

The mass of the first asteroid is = 1 million kg = 1000000 Kg.

The mass of the second asteroid is = 50000 Kg.

The distance between both the asteroids = 400 m

We know,

The force of gravity between two objects can be determined by using the relationship

[tex]F_g=\frac{M_1M_2}{d}[/tex]

So, for determining the value of the force of gravity we will put the value of m1, m2 and d in the above formula:

Thus we will get:

[tex]F_g=\frac{1000000\times 50000}{400}=125,000,000=125\times 10^6\:N[/tex]

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According to the second law, entropy always rises in closed systems. Let's use the growing of a leaf as an example. The sun emits low-entropy radiation that the leaf absorbs and then emits higher-entropy radiation into its surroundings.

The leaf is encouraged to reduce its own entropy in order to sustain the overall process's required increase in entropy as a result of this significant entropy increase.

Using this illustration, we can draw the conclusion that living things adhere to the second law of thermodynamics. second law of thermodynamics

A process that exchanges or transfers heat can result in a certain amount of useful work, according to the second law of thermodynamics.

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The cell cycle advances from G1 phase to S phase when the cyclin–CDK complex phosphorylates RB.

The management of eukaryotic cell proliferation depends on the precise transition from G1 phase to S phase of the cell cycle, and its dysregulation encourages oncogenesis. Growth-dependent cyclin-dependent kinase (CDK) activity encourages DNA replication and starts the transition from G1 to S phase during G1 phase.

By causing alterations in transcription across the entire genome, CDK activation sets off a positive feedback loop that drives up CDK activity even more, committing the cell to division. G1-S transcripts produce proteins that control subsequent cell cycle processes. The intricate molecular mechanisms that regulate the temporal order of transcriptional activation and inactivation, identify distinctive functional subgroups of genes, and link cell cycle-dependent transcription are just now starting to come into focus as a result of recent research.

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Answer: Solid disk have the greater acceleration than the hoop.

Explanation:The body will have the maximum implicit energy at theThe body will have the maximum implicit energy at the top, but as the body rolls down the aeroplane , its implicit energy thresholds transubstantiating into translational and rotational kinetic energy. The body which will have a advanced moment of indolence will have advanced rotational kinetic energy and lower translational kineticenergy.However, also a circle has a lesser moment of indolence than a solid fragment, If we consider the case of a circle and a solid fragment. So the final speed of the circle is lower than the solid fragment. Acceleration will be the change in speed. So the acceleration of the solid fragment will be advanced than the circle. top, but as the body rolls down the aeroplane , its implicit energy thresholds transubstantiating into translational and rotational kinetic energy. The body which will have a advanced moment of indolence will have advanced rotational kinetic energy and lower translational kineticenergy.

However, also a circle has a lesser moment of indolence than a solid fragment, If we consider the case of a circle and a solid fragment. So the final speed of the circle is lower than the solid fragment. Acceleration will be the change in speed. So the acceleration of the solid fragment will be advanced than the circle.

Answer:

Electromagnetic induction was discovered by Micheal Faraday.

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The pair of work and energy is similar.

Among all the given pairs the pair of work and energy are similar because they have similar units.

According to the work energy theorem, the total work done on a body by all the forces combined is equal to the change in kinetic energy of the body.

W = ∆K

According to the principle of homogeneity,

If two quantities are equal then they must have similar units.

In the case of energy and work both of them has the unit Joule. Because there equal as per the work energy theorem.

Work and power, Momentum and energy, force and power all have different units so they are not similar pairs.

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A pendulum requiring exactly one second for each swing in either direction or two seconds for a complete vibration and having a length between centers of suspension and oscillation of 99.353 centimetres at sea level in latitude 45 degrees.

When two dice are rolled there are 36 possible outcomes. The sample for two diced named A and B can be written as follows:

S= {(1,1), (1,2), (1,3),(1,4),(1,5),(1,6), (2,1),(2,2),(2,3),(2,4), (2,5),(2,7),(3,1),(3,2),(3,3),(3,4),(3,5),(3,6),(4,1),(4,2),(4,3),(4,4),(4,5),(4,6),(5,1),(5,2),(5,3),(5,4),(5,5),(5,6),(6,1),(6,2),(6,3),(6,4),(6,5),(6,6)}

This question can be solved using concept of probability and sample space.

a) probability of rolling a 7

Possible outcomes: (6,1),(1,6),(2,5),(3,4),(4,3),(5,2)

Probability= 6/36=1/6

b) Probability of a double

possible outcomes: (1,1),(2,2),(3,3),(4,4),(5,5),(6,6)

probability= 6/36= 1/6

c) probability of rolling a 7 or 8

= probability of rolling 7+ probability of rolling 8

= [tex]\frac{6}{36} +\frac{5}{36}= \frac{11}{36}[/tex]

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The ratio of the three circles they draw is equal to the distances from the stations to the epicenter.

Scientists use triangulation to find the epicenter of an earthquake. If seismic data are collected from at least three different locations, their intersection can be used to determine the epicenter. Each earthquake is recorded by numerous seismometers placed in different directions.

The epicenter is the point on the surface directly above the earthquake. A seismic station uses seismometer recordings to detect earthquakes. Determining the epicenter of an earthquake requires records from three separate seismic stations. Triangulation is a method of uniquely identifying earthquakes using distance information determined from three seismic stations.

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8.1 * [tex]10^{5}[/tex] Hz is a frequency of this light when predominant wavelength emitted by an ultraviolet lamp is 370 nm .

fλ = c

where f- Frequency

          λ - Wavelength

          c- speed of light

 f= c/ λ

  = 3 * [tex]10^{8}[/tex]/ 370

  = 8.1 * [tex]10^{5}[/tex] Hz

A waveform signal that is carried in space or down a wire has a wavelength, which is the separation between two identical places (adjacent crests) in the consecutive cycles. This length is typically defined in wireless systems in meters (m), centimeters (cm), or millimeters (mm).

The wavelength, which will also apply to troughs, is the separation between two wave crests. The number of vibrations that span a particular area in a second is known as the frequency, which is measured in cycles per second (Hz) .

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When the students close the circuit and the fan blades start to spin, energy is transformed from electrical energy to mechanical energy.

Electrical energy is energy generated from the flow of electric charge through a conductor. This energy is utilized in virtually all modern-day appliances, from lightbulbs to cell phones to electric cars. It is created in power plants, harnessed through transmission lines, and distributed to consumers. Electrical energy can be converted into other forms of energy, such as heat or light, and can be used to power machines and equipment.

This is done by the battery supplying electrical energy to the switch and the fan, which then converts the energy into rotational energy. This is what causes the fan blades to spin and produces mechanical energy. The mechanical energy produced by the fan is then used to create air movement, which is another form of mechanical energy.

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The heat absorbed if the efficiency of the engine is 55% is determined as 1,000 J.

The heat absorbed by the system is the positive heat gain by the system or  the useful energy of the system.

From the fist law of thermodynamics, when heat is added to a system or absorbed by the system, the system gains heat.

Mathematically, the first law of thermodynamics is given as;

ΔU = q + w

where;

The heat absorbed by the system is calculated as follows;

q = ΔH / ( 1 - e )

where;

q = 450 J / ( 1 - 0.55 )

q = 450 J / 0.45

q = 1,000 J

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The orion nebula, m-42,  is a hot, thin cloud of glowing gas, so its spectrum is (d) a few bright lines against a dark background.

The Orion Nebula is it a cloud of gas?

One of the best-known celestial features is the Orion Nebula, often known as M42. This cloud of gas and dust, the middle "star" in Orion's dagger hanging below his belt, is so dazzling that it can be seen with the unaided eye even from a distance of more than 13 quadrillion kilometers (8 thousand trillion miles).

Why is Orion so crucial?

One of the starry sky's most intriguing and significant constellations is Orion. One reason why astronomers are drawn to it is that it contains one of the Milky Way Galaxy's closest and most active star nurseries (the Orion Nebula).

The Orion Nebula's gas glows for what reason?

The Trapezium and Nebula are located in front of a cold, dusty "giant molecular cloud" that contains regions of active star formation, around 1500 light years away. A blister on the molecular cloud's front edge gets electrified by the stars of the Trapezium, making it glow.

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Upon calculation A=[tex]\left[\begin{array}{ccc}3&5\\0&0\\\end{array}\right][/tex]    and A'= [tex]\left[\begin{array}{ccc}0&1\\0&3\\\end{array}\right][/tex]

This question can be solved using the concept of matrices.

A matrix is a rectangular array of integers divided into rows and columns. In mathematics, a matrix is an array of integers that is arranged in a rectangular pattern and split into rows and columns. They are often expressed by enclosing all of the numbers included between square braces.

According to the question given here

T₁(x,y)= (x-3y,3x+5y)

and

T₂(x,y)= (y,0)

Now it is clearly mentioned that T= T₁*T₂

T(x,y)= T₂[T, (x,y)]

T(x,y)= T₂(x-3y,3x+5y)

T(x,y)= (3x+5y,0)

T(1,0)= (3*1+5*0,0)= (3,0)

T(0,1)= (3*0+5*1,0)= (5,0)

which means A=[tex]\left[\begin{array}{ccc}3&5\\0&0\\\end{array}\right][/tex]

Now to find A'

T'= T₁*T₂

T'(x,y)= T₁[T₂(x,y)]

T'(x,y)= T₁(y,0)

T'(x,y)= (y-3*0,3y+5*0)

T'(x,y)= (y,3y)

T'(1,0)= (0,0)

T'(0,1)= (1,3)

which gives us A'= [tex]\left[\begin{array}{ccc}0&1\\0&3\\\end{array}\right][/tex]

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When a rock on a string is spun in a horizontal circle, the speed is doubled, quadrupling the tension in the string.

When the rope breaks, there is no force in the radial direction, thus the stone flies off tangentially because of inertia. Until the stone is attached to a string, the tension in the string causes centripetal force and centrifugal force along in radial direction of motion.

What is Tension in the string?

Tension is the force that is sent through a rope, string, or wire when two opposing forces pull on it. Along the whole length of the wire, the tension force pulls energy equally on the bodies at the ends.

Every physical object that comes into contact with another one exerts a force on it. These contact forces have names based on the types of things they are applied to. One of the forces exerted on an object, such as a rope, cable, or chain, is tension.

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A moon has more mass than the planet it circles and less mass than a star.

Do planets have a greater mass than stars?

By this definition, "stars" must be larger than planets in terms of mass. The size of a white dwarf would be comparable to that of a moon or small planet, but its mass would be approximately 200–1300 times that of Jupiter. Even more extreme are neutron stars, which are about the size of an asteroid but have a mass of several thousand Jupiters.

Why is the weight of the same object different on different planets Class 7?

The weight of an object is determined by its mass and the gravitational force that it experiences. The separation between two objects affects how strong gravity is. Because of this, an object weights differently on many planets.

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In general, the center of gravity of an object can be determined by suspending the object from a single point and observing the object's balance. If the object is in balance, then the point of support is coincident with the object's center of gravity. If the object is not in balance, then the point of support is not coincident with the object's center of gravity, and the object will rotate or tilt until it comes to rest in a stable position.

If the clamp used to support the meter bar were inverted, it would still be possible to determine the center of gravity of the bar by suspending it from the inverted clamp and observing its balance. However, it may be more difficult to balance the bar in this configuration, as the clamp would be applying a force to the bar that is not aligned with the bar's center of gravity. This could cause the bar to rotate or tilt, making it more difficult to determine its center of gravity accurately.

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A solar day is 0.50001917 times longer than a sidereal day if the earth's orbital period is shortened to six months.

Earth is just a rocky, earthy planet and is home to us. There are mountains, valleys, canyons, plains, and much more on its stable and dynamic surface. Being an ocean planet, Earth is unique. The Earth's surface is 70% covered by water.

1 Sidereal year = 365.256 days

1 Solar year (1 tropical year) = 365.242 days

The length of time inside a sidereal year is equal to 365.256/2 days, or 182.628 days, if the earth's orbital period is six months.

1 Solar day = 182.256/365.242 sidereal days

1 Solar day = 0.50001917 sidereal day

A solar day is 0.50001917 times longer than a sidereal day if the earth's orbital period is shortened to six months.

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The complete question is-

Solar and Sidereal Days. Suppose Earth orbited the Sun in 6 months rather than 1 year but had the same rotation period. How much longer would a solar day be than a sidereal day? Explain.

Sherwin's resulting velocity after the collision is  18.94m/sec. if his initial velocity is 12m/sec and mass of 150kg.

It is given that Sherwin has initial velocity and Lia is going to start the bumper car. It means that initial velocity of Sherwin is 12m/sec and initial velocity of Lia is 0m/sec. Since, the collision is elastic, it means that energy will not lost during the collision and momentum will remain conserved.

So, applying the law of conservation of momentum which is

Initial momentum =Final momentum

=>Initial momentum of Sherwin is=mass × velocity

=>Initial momentum of Sherwin=150 × 12m/sec

Now, initial momentum of Lia is =mass × velocity

=>Initial momentum of Lia is =95×0=0m/sec

Now, final momentum of Sherwin=0m/sec since collision is elastic

Also, final momentum of Lia is =95×v

According to the formula, we get

=>150 × 12 +0 =0  + 95×v

=>95×v=150 × 12

=>v=(150 × 12)/95

=>v=1800/95

=>v=18.94m/sec

Hence,  Sherwin velocity is 18.94m/sec.

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if the mass of the satellite increases, the orbital velocity will increase, and if the radius increases then the orbital velocity will decrease.

Orbital velocity is the speed at which a satellite must move to remain in orbit, and is determined by a combination of the satellite’s mass and the radius of its orbit. The formula for orbital velocity is:   V = sqrt(GM/R)  Where G is the gravitational constant, M is the mass of the satellite, and R is the radius of the orbit.  If the mass of the satellite increases, the orbital velocity will increase. This is because the equation for orbital velocity is directly proportional to the mass of the satellite. That is, the higher the mass, the higher the orbital velocity.  If the radius of the orbit increases, the orbital velocity will decrease. This is because the equation for orbital velocity is inversely proportional to the radius of the orbit. That is, the larger the radius, the lower the orbital velocity.

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1.33m/s^2 is the acceleration. when a billiard ball is decelerating at a constant rate. its initial velocity is 8m/s. after 1.5 seconds it is travelling at 6m/s.

The rate at which a moving object's velocity changes is known as acceleration. It gauges the speed of velocity changes. Examples of acceleration include riding a carousel and traveling at a constant speed around a bend on a road.

The equation a = v/t denotes acceleration (a), which is the change in velocity (v) over the change in time (t).

a = (v_f - v_i) / Δt

a= 6m/s  - 8m/s / 1.5 seconds

a=-1.33m/s^2

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The effect of doubling the water mass on the temperature change, and why do you think this happened is  doubling the mass will double the temperature change.

It lowers the temperature. Because the water temperature lowers as the bulk of the cylinder grows, it will result in a cooler year. Thermal expansion happens with heating. The mass stays constant. The loudness goes up. And as a result, the density drops. The average kinetic energy of an object's particles rises with increasing temperature. The object's thermal energy grows as the average kinetic energy of its particles rises. As a result, an object's thermal energy rises as its temperature does.

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Observations of young stars tell us that when the Sun was young the solar wind was stronger than it is today.

The proto-planetary disc's gas and dust would have been cleaned away by the young Sun's solar wind after three to ten million years, pushing it into interstellar space and putting an end to the planets' formation.

The solar nebular disc model, often known as the solar nebular model, is the most extensively used current variation of the nebular hypothesis.

The planets' almost circular and coplanar orbits, as well as their motion in the same plane as the Sun's spin, were all explained by this theory, along with a number of other features of the Solar System.

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Dog is seated 1.25 metres from the centre and rotates at a tangential speed of 2.0 metres per second. If the dog weighs 19.3 kg, the centripetal force acting on it will be 61.76 N.

A total net force  acting on an object moving in a circular motion is known as a centripetal force.

It is given that radius(r) of the merry go round = 1.25m

tangential speed of the merry go round (v) = 2m/s

Mass of the dog (m) = 19.3kg

Centripetal acceleration (ac) is calculated as = v^2/r

So ac = (2x2)/1.25 = 3.2m/s^2

According to centripetal force(Fc) = mxac

Then Fc = 19.3 x 3.2 = 61.76N

Hence the centripetal force acting on the dog is 61.76N

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