a child and his sled have a combined mass of 40 kg. the sled/child system has a speed of 5 m/s speed at the top of a 10 m high slope. the sled and child descend the hill linearly along a distance of 100 m. determine the speed of the child and sled at the bottom of the 100 m slope, if the force of friction between the sled and snow is 20 n.

If the star radiates uniformly in all directions, the total power output of the star is 2.37 x 10²⁷ W.

The formula for the intensity of the light at a distance R from the source of light (which is star in this case) is given by,

I = P/A

I is the intensity,

P is the power,

A is the area.

We can write,

P = IA

Intensity is given to be 15.4 W/m².

A = πR²

Here, we will take the value of R is 7 x 10¹² m.

So,

A = π( 7 x 10¹²)²

Putting the values,

P = IA

P = 15.4 x π x ( 7 x 10¹²)²

P = 2.37 x 10²⁷ W.

The power output of the star is 2.37 x 10²⁷ W.

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The direction of net force at all points in the projectile's path is downwards towards the ground.

F = m a

F = Force

m = Mass

a = Acceleration

F ∝ a

The direction of net force is influenced by the direction of acceleration.

In a projectile motion, if the air resistance is considered negligible, there will be no acceleration in horizontal direction. Because, there will be no forces acting in horizontal direction. The only force acting on the projectile is the force of gravity. Gravity pulls the object downwards throughout its motion. So the direction of net force will be downwards at all points in the projectile's path.

Therefore, the direction of net force at all points in the projectile's path is downwards towards the ground.

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Answer:

Light can travel through a glass or through a vacuum

To reduce the uncertainty in the measurement of the period in oscillation.

A mechanical device that oscillates swings from side to side. A peg-and-slot can convert it into a rotary motion (rotating in a circle). The similar technique can be used to convert rotary motion to oscillating motion.

Sine and cosine functions can be used to describe the motion of a simple harmonic oscillating system where the restoring force is directly proportional to that of the displacement and acts in the direction opposite to that of displacement. One illustration is a weight fastened to a spring. The weight is in equilibrium when it is at rest. If the weight is reduced, the mass is subject to a net restoring force (potential energy)

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The angle of the rope makes with the vertical when the ball's kinetic energy is halved is 14.78°.

Parameter

When the ball is pushed horizontally and moves from point A to point B where the ball's kinetic energy halves, the law of conservation of energy applies.

Mechanical energy at A = Mechanical energy at B

Epa + Eka = Epb + EKb

Eka - Ekb = EPb - Epa

[tex]Ek_A -\frac{1}{2}Ek_A = mgh_B - mgh_A[/tex]

[tex]\frac{1}{2}Ek_A = mg \: (h_B - h_A)[/tex]

[tex]\frac{1}{2} \times \frac{1}{2} m v_A^2 = mgh[/tex]

[tex] \frac{1}{4} v_A^2 = gh[/tex]

[tex]gh = \frac{1}{4} \times 1.3^2[/tex]

gh = 0.4225

[tex]h = \frac{0.4225}{9.8}[/tex]

h = 0.043 m

Look at the picture

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Answer: B. Energy

Explanation:

The Energy is the quantity that only depicts the magnitude and not the direction, hence it is a scalar quantity, so option B is correct.

In physics, energy is the capacity to do work. It might be potential, kinetic, thermal, electrical, chemical, radioactive, etc. Heat and work are further examples of energy being transferred from one body to another. Once it has been transmitted, energy is always allotted based on its nature. Thus, heat transmission could result in thermal energy while effort could produce mechanical energy.

The scalar quantity means they have only the magnitude and no direction. The velocity of any object tells the speed at which it is moving and its direction also, and the force applied to an object also tells the magnitude with direction, the momentum of an object is dependent on the force, so it is also a vector quantity

Therefore, Energy is the quantity that only depicts the magnitude and not the direction, hence it is a scalar quantity.

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Amplitude does not affect wave speed because amplitude is a measure of the wave energy as it oscillates. This implies that movement of the wave is separate from the movement indicated by the sleep of the wave.

By increasing the tension, the wave speed increases and hence frequency increases. Greater tension implies greater acceleration of particles, which means greater speed of particles and hence greater speed of wave.

As we know, speed = frequency * wavelength. This clearly means that speed is directly proportional to the frequency such that when frequency increases, speed also increases and vice versa.

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☆ Hello ☆

We first apply the data to the problem.

Data:

Then, we apply the formula that is.

Formula:

Finally we develop the problem.

Developing:

The distance traveled is 400 kilometers.

Uniform line movement

Rectilinear uniform motion is one in which an object moves in a straight line, it is a single direction, with a constant speed. When we speak of constant speed we mean that the movement maintains the same speed; that is, the object does not move faster or slower, always at the same speed.

We have that the data is:

Speed (V) = 80 km/h

Distance (d) = ?

Time (t) = 5 h

The formula for uniform motion is:

[tex]\boxed{\large\displaystyle\text{$\begin{gathered}\sf \bf{V=\frac{d}{t} } \end{gathered}$} }[/tex]

We clear for the distance

[tex]\boxed{\large\displaystyle\text{$\begin{gathered}\sf \bf{d=v*t} \end{gathered}$} }[/tex]

[tex]\boxed{\large\displaystyle\text{$\begin{gathered}\sf \bf{d=80\ \frac{km}{\not{h}}*5\not{h} } \end{gathered}$}}[/tex]

[tex]\boxed{\boxed{\large\displaystyle\text{$\begin{gathered}\sf \bf{d=400 \ km} \end{gathered}$}}}[/tex]

When rain is falling vertically at 8m/s then the speed of the car is calculated to be 4.618 m/s.

The velocity of the raindrops adds to the velocity of the car to produce a velocity of the rain relative to the car.

As the surface becomes rougher, friction increases and on rainy days, we are more likely to slip because water acts as a lubricant between feet and the ground. Dry friction is converted to fluid friction by rainwater.  Rain drops have a uniform type of motion

Given rain is falling vertically with 8 m/s speed

and rain drop makes an angle of  30°

As we know that, tan∅ = V (horizontal) / V (vertical)

Hence,  V (horizontal)= tan ∅ *  V (vertical)

= tan (30° ) * 8

speed of the car​ = 4.618 m/s.

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Answer:

As P is increased from mg(sinθ−μcosθ) to mg(sinθ+μcosθ) frictional force will change from mgcos ( upwards parallel to inclined plane) to 0 to mgcos (downwards parallel to inclined plane). Under the approximation of linear variation of P the correct option is A.

Distance between nodal planes is calculated to be 2.4m, when given frequency is 125MHz .

A radio transmitter is an electronic circuit that transforms electric power from a power source into a radio frequency alternating current to the antenna and then the antenna radiates the energy from this current as radio waves.

As we know that, F= c/λ

where c -->speed of light and λ --> wavelength

λ = 2L/n

where; L --> length and n -->nodes

Given frequency = 125 MHz

λ = c / F

= 3 * 10⁸/ 125 *10⁶

λ= 2.4

Hence, distance between nodal planes is 2.4m

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Answer:

A quality of matter that is unrelated to a change in its chemical makeup is called a physical property.

Examples of physical properties of matter:

Physical properties are any qualities of matter that may be felt or seen without changing the sample's chemical composition.

Due to the wide range of features that make up physical attributes, they are further separated into intensive and extensive as well as isotropic and anisotropic categories.

Any characteristic that can be recognized and measured by sight, hearing, touch, smell, or other senses without evoking a chemical reaction is referred to as a physical property. Examples of physical traits are:

Color, Shape, Volume, Density, Calorific value, Boiling point, Viscosity, Pressure, Solubility, electrical current

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The animal with the lowest bar on that bar graph would be the mountain lion.

A bar graph is a visual representation of data that uses rectangular bars having lengths according to the values they represent. A bar graph, which can be shown horizontally or vertically, compares sets of data.

According to the question, mountain lions had the lowest bar on a bar graph since they have the smallest population 150 of all the species.

Bar graphs are a way of representing the numerical data sets of different aspects on a graph paper that allows easy calculations and conclusions.

On the graph sheets, the quantitative method is shown as bars, which show their values.

The answer to the query indicated that Mountain Lions would have the graph's lowest bar.

The picture provided below shows the plotted and associated bar graph again for the aforementioned query.

The vertical or y-axis represents the animal population, while the horizontal or x-axis shows the various species of animals.

Mountain lions are the species with the least amount of residents in the area.

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The question is -

If the data below were put into a bar graph, which animal would have the lowest bar on the bar graph? Number of Individuals in a Rocky Mountain Forest Organism Population Mountain lions 150 Bobcats 300 Coyotes 10,000 Deer 25,000 mountain lions bobcats coyotes deer Mark this and return Save and Exit.

Answer: the answer is A

Explanation:i got it from a friend it was right

The number of elements pictured in the above image is 3 (option C).

Element are any one of the simplest chemical substances that cannot be decomposed in a chemical reaction or by any chemical means and made up of atoms all having the same number of protons.

There are about 118 chemical elements, each with its own type of atom. Everything in the universe contains the atoms of at least one or more elements. The periodic table lists all the known elements, grouping together those with similar properties.

According to this question, elements are represented by different colours. Each colour represents each element.

The three colours are as follows:

This means that there are three elements in the above image.

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With wavelengths of around 10-1000 m, radio waves used by cell phones to communicate with cell towers are far too big to be ionizing. In reality, WiFi runs at very specific frequencies, 2.4 GHz or 5 GHz, which correspond to wavelengths of 12 cm or 6 cm, respectively.

Since radiofrequency waves are electromagnetic fields rather than ionizing radiation like X-rays or gamma rays, they cannot ionize or destroy chemical bonds in living organisms.

The signal is transformed back into the data that was first sent by the transmitter when the radio waves reach a receiver. Your voice is sent through radio waves to the person you are contacting when you use a cell phone as a transmitter.

The primary means of communication between mobile phones and neighboring cell towers is through RF waves, an electromagnetic spectrum energy type.

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The semi-infinite body shall be considered as a system that is bounded by one surface and that extends to infinity in other directions.

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The best model according to vespr  model has the best arrangement of a given number of electron domains and is the one with less repulsion among the  electrons

The VESPR model is also known as VSEPR theory or valence shell electron pair repulsion theory. This model provides a three-dimensional structure for the arrangement of electrons within an atom. According to this model, valence shell electrons participate in chemical bonding processes. Molecular geometry shows that only valence shell electrons participate in ionic or molecular bonding.

The theory is based on the premise that repulsion between the pairs of valence electrons in all atoms and the atoms will always tend to arrange  themselves in a manner in which this electron pair repulsion is minimized

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The moment of inertia of the boxer's forearm will be 0.525kg.[tex]m^{2}[/tex]

In physics, it means quantitative measure of the rotational inertia of the body. As an example, the opposition that the body exhibits to having its speed of rotation about an axis altered by the application of a torque (turning force). The axis may be internal or external and may or may not be fixed.

From the question given, the triceps muscle in the back of the upper arm extends the forearm of a professional boxer when he extends his arm,
Torque generated due to this force is,

τ = F * r
τ = torque is generated

F = force exerted = 2903n
r = the radius of the lever arm = 2.35cm = 0.0235m

Now let's use the torque formula
τ = 2903N * 0.0235m
τ = 68.2205 N.m

Next, we want to find the moment of inertia of the boxer's forearm by calculating the relation between torque and moment of inertia and angular acceleration,

τ = torque = 68.2205Nm
I = moment of inertia
α = angular acceleration = 130 rad / s²

τ = Iα
68.2205 = I*130rad/s²
I = 0.525 kg.m² (rounded)

Therefore, the value of moment of inertia is 0.525kg.m²

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Leveling the amount of work done at each work station is an example of Value Stream Mapping.

Value stream mapping was developed out of lean manufacturing, which companies use to create a visual guide of all the components required to deliver a product or service for the purpose of analyzing and optimizing the entire process.

The process of creating a value stream map takes all the people, processes, information, and inventory you need and presents them in flowchart form.

Learning core Lean Six Sigma (LSS) tools can help you become more attractive to new employers or increase the value you offer in your current workplace in a number of ways, including:

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a ) When they reach the ground, rock B has greater velocity.

b ) Both rocks have the same acceleration

c ) Rock A and Rock B arrives at the same time

According to law of conservation of energy,

1 / 2 m u² + m g hi = 1 / 2 m v² + m g hf

u = 0

hf = 0

m g hi = 1 / 2 m v²

v = √ ( 2 g / m ) √ hi

v ∝ √ hi

a ) hi of rock A will be higher because it reaches a certain height above the ground which will be considered as initial height for rock A. So, the final velocity of rock A is higher.

b ) Both the rock are affected by only the force of gravity. So they will have the same acceleration of 9.8 m / s²

c ) If air resistance is ignored,

s = u t + 1 / 2 at²

For an object that is dropped,

u = 0

a = g

s = at² / 2

t = √ ( 2 s / g )

It can clearly be seen that no matter what height an object might be dropped from, if air resistance is ignore they will fall at the same time.

Therefore,

a ) When they reach the ground, rock B has greater velocity.

b ) Both rocks have the same acceleration

c ) Rock A and Rock B arrives at the same time

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A cylindrical resistor of radius 4.5 mm and length 2.0 cm is made of material that has a resistivity then current density J is  1.12 × [tex]10^{5}[/tex]

Since P = i^2 r = (J^2) (A^2) R

J = 1/A [tex]\sqrt{P/R}[/tex]

Current density (J)  = 1.12 × [tex]10^{5}[/tex]

A material's electrical resistivity, also known as specific electrical resistance or volume resistivity, is a key characteristic that quantifies how effectively it resists electric current. A substance that permits electric current to flow easily has a low resistance. The Greek letter is often used to signify resistivity (rho). Ohm-meters (m) are the metric unit for electrical resistivity.  For instance, the resistivity of a material is 1 m if it has sheet contacts on two of its opposing faces and has a 1 resistance between them.

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Answer:

To say we have a 12.0-V battery implies that its terminals have a 12.0-V likely contrast. At the point when such a battery moves charge, it puts the charge through an expected distinction of 12.0 V, and the charge is given an adjustment of potential energy equivalent to Δ U = q Δ V .

six cells

There are six cells to a 12 volt lead corrosive battery. A battery cell's greatest capacity to convey current (amps).

A 6 cell lithium particle pack has an ostensible voltage of 21.6V to 22.2V and a most extreme charge voltage of 25.2 volts

Explanation:

There is a 40000 N/C downward electric field between the plates.

Potential difference between the plates V = 2000 V

Plates separation d = 5 cm = 0.05 m

power source E=V/d

Electric field E=40000 N/C downhill

The electric force per unit of charge is what is meant when we talk about an electric field. It is presumable that the field's direction matches the direction in which a successful test charge would feel force. The physical surroundings of a system of charged particles are also described. Electric fields are composed of electric charges and time-varying electric currents. The electromagnetic field, one of nature's four primary interactions, or forces, appears as both electric and magnetic fields.

In electrical technology, electric fields are used, and significant in many branches of physics. For instance, the attracting force in atomic physics and chemistry is the electric field.

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The force needed to bring a car to rest from a speed is 2,541 Newton.

The formula in non-uniform motion

v = u + at

v² = u² + 2ad

[tex]d = u \times t + \frac{1}{2} \times a \times t^2[/tex]

Because the final speed is km/h, we must convert it into m/s

v = 85.0 km/h

v = [tex]85.0 \times \frac{1 \: km}{1 \: hour}[/tex]

v = [tex]85.0 \times \frac{1,000 \: m}{3,600 \: s}[/tex]

v = [tex]\frac{850}{36}[/tex]

v = 23.6 m/s

Calculate the acceleration

v² = u² + 2ad

23.6² = 0² + (2×a×15)

556.96 = 230a

[tex]a = \frac{556.96}{230}[/tex]

a = 2.42 m/s

Formula to find the force F=ma

F = ma

F = 1,050×2.42

F = 2541 Newton

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Answer:

10 m/s

Explanation:

Kinetic energy= [tex]\frac{1}{2}[/tex]mv² where m is mass and v is velocity.

We have to make v the subject so we should rearrange the equation

K=[tex]\frac{1}{2}[/tex]mv²

v²= [tex]\frac{K}{0.5*m}[/tex] (use algebra)

v²= 7/0.5×0.140

v²=100

v=√100

v=10 m/s

We can confirm this by using the kinetic energy formula.

K=[tex]\frac{1}{2}[/tex]×0.140×10²

K= 7 J

Hence it is proved that velocity is 10 m/s

The acceleration for the 40kg and 60 kg person will be 3 m / s² and - 2 m / s² respectively if the 60kg man pushes the 40kg woman with 120 N force.

F = m a

F = Force

m = Mass

a = Acceleration

For 40 kg woman,

m = 40 kg

F = 120 N

a = F / m

a = 120 / 40

a = 3 m / s²

For 60 kg man,

According to Newton's third law of motion, for every action there will be an equal and opposite reaction. So the 40 kg woman will push back with a force of - 120 N.

a = - 120 / 60

a = - 2 m / s²

The negative sign indicates negative direction.

Therefore, the acceleration for the 40kg and 60 kg person will be 3 m / s² and - 2 m / s² respectively

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Using the concepts of gravitation, we find that it is true that tides are the periodic short term change in the height of the ocean surface at a particular place, generated by the long wavelength progressive waves that are caused by  interaction of gravitational force of the moon and sun.

Gravitational force is one of  basic forces of nature. It is a force that acts between two bodies and it is always attractive in the nature. Gravitational force is the force with which the objects are attracted to the centre of  earth. The motion of the planets and the moon are  governed by this force

Kepler’s first law All the planets will revolve around the sun in an elliptical orbit with the sun at one of the focus.

Hence, tides are the periodic short term change in the height of  the ocean surface at a particular place, generated by the long wavelength progressive waves that are caused by  interaction of gravitational force of the moon and sun is true.

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The total amount of energy remains the same. It just changes from one form to another as the person swings back-and-forth. Statement (C) is true.

Energy is the ability to perform work in physics. It could exist in several different forms, such as potential, kinetic, thermal, electrical, chemical, radioactive, etc. Additionally, there is heat and work, which is energy being transferred from one body to another.

When Manuel was watching his younger siblings on the swing set; the motion of swinging is a kind  of simple harmonic motion where total energy remains conserved. But kinetic and potential energy are continuously exchanged in simple harmonic motion.

Potential energy is at its peak and kinetic energy is zero when you are farthest from the equilibrium point. The kinetic energy is at its peak and the potential energy is zero at the equilibrium point. The oscillating body's kinetic and potential energy values change at other points in its motion. So, the total amount of energy remains the same. It just changes from one form to another as the person swings back-and-forth.

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The ball's initial velocity  is  14 m/s

Since the equation of motion we referring to for  calculating  the initial velocity are :

s=ut+1/2at²  ....1

v²= u²+2as .... 2

where u and v are initial and final velocity, t is the time taken, a is the acceleration due to gravity and s is the distance or we can also  say the height .As we are given h₁ and  h₂ which are 2.45 m and  7.45 m and the time is taken, t which is  1.45 s, and at last we are having a = -9.8ms^-2

using the 2 equations, we get  

v₁= √(u²−2gh₁),

from equation 1, we get

h₂ =√(u₂−2gh₁t)−1/2gt₂

there the initial velocity will be:

u= √(((h₂+1/2gt²)/t)²+2gh1

 =√(((7.35+1/2*9.80*(1.45)^2)/1.45)^2+2×9.80×2.45)

 = 14

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1.065 m / s is the average speed (in m/s) of the particle.

Circumference = 2[tex]\pi[/tex]r

238.14= 2 x 3.14159 x38 cm

238.14 x 17 rotations / 38seconds

= 106.53 cm / second

106.53 cm / 100 cm per meter

= 1.065 m / s

Average speed is the total distance travelled by an object during a certain time interval. Average speed is a scalar quantity. It is represented by size and has no direction.

The formula for average speed is found by calculating the ratio of the total distance travelled by a body to the time required to travel that distance.

The average speed equation is formulated as follows:

Total distance traveled / Total time travelled

[tex]{S_{AVG}}= \frac{D_{totale}}{T_{totale}}[/tex]

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