3. Mario is planning to conduct an experiment to determine which disinfectant is best for killing bacteria that are often found in kitchens.
Which of the following would be the most logical dependent variable for his experiment?
A. type of disinfectant
B. source of bacteria
C. amount of disinfectant
D. number of bacteria that survived using the disinfectant

Final answer:

The mechanical advantage of the machine is 4, indicating it multiplies the input force by a factor of four.

Explanation:

The student is asking about the concept of mechanical advantage (MA), which is a measure of the force amplification achieved by using a tool, mechanical device, or machine system. The mechanical advantage is calculated as the ratio of the output force to the input force. In this case, a machine lifts a load with an output force of 160N when an input force of 40N is applied. Thus, the mechanical advantage of the machine is calculated by dividing the output force by the input force.

MA = Output Force / Input Force = 160N / 40N = 4.

So, the mechanical advantage of the machine is 4, which means the machine multiplies the input force by four times.

Answer:

(C) 16

Explanation:

Given:

The amplitude of first wave (s₁) = 20 mm

The amplitude of second wave (s₂) = 5 mm

Intensity of first wave = Iₓ

Intensity of second wave = [tex]I_y[/tex]

The intensity associated with a wave depends on the amplitude of the wave.

The intensity (I) is directly proportional to the square of the amplitude (s) of the wave and is expressed as:

[tex]I=ks^2\\Where\ k\to constant\ of\ proportionality[/tex]

Now, the intensities of the two waves are given as:

[tex]I_x=ks_1^2=k(20)^2\\\\I_y=ks_2^2=k(5)^2[/tex]

Dividing both the intensities, we get:

[tex]\frac{I_x}{I_y}=\frac{k(20)^2}{k(5)^2}\\\\\frac{I_x}{I_y}=\frac{400}{25}\\\\\frac{I_x}{I_y}=16[/tex]

Therefore, the option (C) is correct.

The intensity of a wave is directly proportional to the square of its amplitude. The ratio of Ix to Iy is 16. Therefore, the correct answer is C. 16.

The intensity (I) of a wave is related to its amplitude (A) by the following equation:

I = (1/2) * ρ * v * ω^2 * A^2

Where:

I is the intensity.

ρ is the density of the medium through which the wave is traveling.

v is the velocity of the wave in the medium.

ω is the angular frequency (equal to 2π times the frequency of the wave).

A is the amplitude of the wave.

Since both waves have the same frequency and are traveling through the same medium, ρ and v will be the same for both waves. Therefore, we can simplify the intensity ratio (Ix/Iy) using the amplitude ratio (Ax/Ay) as follows:

Ix/Iy = (1/2) * (ρ * v * ω^2 * Ax^2) / (1/2) * (ρ * v * ω^2 * Ay^2)

The ρ, v, and ω^2 factors cancel out:

Ix/Iy = (Ax^2) / (Ay^2)

Now, we can plug in the values given:

Ix/Iy = (20mm)^2 / (5mm)^2

Ix/Iy = (400mm^2) / (25mm^2)

Ix/Iy = 16

So, Ix/Iy = 16.

Therefore, the correct answer is C. 16.

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The correct answer is B) intensity, which denotes the amount of sound wave energy transported per unit time through a unit area.

The amount of energy which is transported past a given area of the medium per unit of time is known as the intensity of the sound wave. Therefore, the correct answer to the question is B) intensity. Intensity is reported in terms of power per unit area (Watts per square meter, W/m2). It is a critical concept in acoustics that describes how sound waves carry energy through a medium, be it a fluid such as air or a solid.

In the process of sound propagation, a vibrating object such as a guitar string, transfers energy to the surrounding medium creating regions of compressions and rarefactions. These regions of varying pressure travel as longitudinal waves, which means they move along the same axis as the direction of the wave. The sound waves carry energy and this energy transfer per unit time across a unit area is what is quantified by the intensity.

Answer:

Explanation:

Hydrogen is the first element on the periodic table. That tells you there is 1 electron.

Angle of refraction: [tex]34.6^{\circ}[/tex]

Explanation:

Refraction is a phenomenon that occurs when light crosses the interface between two mediums.

When this occurs, the ray of light bends, according to Snell's law:

[tex]n_1 sin \theta_1 = n_2 sin \theta_2[/tex]

where

[tex]n_1,n_2[/tex] are the index of refraction of the two mediums, respectively

[tex]\theta_1[/tex] is the angle of incidence (the angle between the incident ray and the normal to the surface)

[tex]\theta_2[/tex] is the angle of refraction (the angle between the refracted ray and the normal to the surface)

In this problem, we have:

[tex]n_1 = 1.513[/tex] (index of refraction of glass for red light)

[tex]n_2 = 1.331[/tex] (index of refraction of water for red light)

[tex]\theta_1=30^{\circ}[/tex] (angle of incidence)

Therefore, the angle of refraction is:

[tex]\theta_2 = sin^{-1}(\frac{n_1}{n_2}sin \theta_1)=sin^{-1}(\frac{1.513}{1.331}sin 30^{\circ})=34.6^{\circ}[/tex]

The angle of the refracted beam in the water is approximately 22.04 degrees.

 To find the angle of the refracted beam in the water, we use Snell's Law, which relates the angle of incidence, the angle of refraction, and the indices of refraction of the two media. Snell's Law is given by:

[tex]\[ n_1 \sin(\theta_1) = n_2 \sin(\theta_2) \][/tex]

where:

[tex]- \( n_1 \) i[/tex]s the index of refraction of the first medium (air in this case),

[tex]- \( \theta_1 \)[/tex] is the angle of incidence in the first medium,

[tex]- \( n_2 \[/tex]) is the index of refraction of the second medium (water in this case),

[tex]- \( \theta_2 \)[/tex]is the angle of refraction in the second medium.

Given that the angle of incidence [tex]\( \theta_1 \)[/tex] is 30 degrees, and assuming the index of refraction for air [tex]\( n_1 \)[/tex]is approximately 1 (since it is very close to 1), and the index of refraction for water \( n_2 \) is about 1.33, we can rearrange Snell's Law to solve for[tex]\( \theta_2 \):[/tex]

[tex]\[ \sin(\theta_2) = \frac{n_1}{n_2} \sin(\theta_1[/tex]

[tex]\[ \sin(\theta_2) = \frac{1}{2.66} \][/tex]

[tex]\[ \sin(\theta_2) \approx 0.3758 \][/tex]

Now, we take the inverse sine (arcsine) to find the angle [tex]\( \theta_2 \):[/tex]

[tex]\[ \theta_2 = \arcsin(0.3758) \][/tex]

[tex]\[ \theta_2 \approx 22.04^\circ \][/tex]

Therefore, the angle of the refracted beam in the water is approximately 22.04 degrees."

Answer:

the chemical energy of the fuel is transformed into the mechanical energy

Explanation:

got it right on USAtestprep

When pressing the accelerator on a car, the chemical  energy of the fuel is transformed into the mechanical energy that makes the car move.

Energy can neither ne created nor be destroyed. But it can be transformed from one form to the other.  The energy transformation does not make any energy loss and the total energy is conserved always.

For instance in batteries, the chemical energy by electrolysis is converted into the electrical energy and which is passed into the electrical devices. This electrical energy further converted to mechanical energy to work fan, motors etc.

When pressing accelerator of the car, the chemical energy released from the combustion of the fuel is converted into the mechanical energy that drives the car ahead.

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Nichrome is a mixture of nickel and chromium. Nichrome Wire is highly resistant to the flow of electricity . This resistance causes an increase in generated heat . It also has the ability to be heated many times without being destroyed. It is is a mixture of nickel and chromium.This heat is powerful enough to heat the water without damaging the wire.

Nichrome wire's high resistance to electric current causes it to heat up and transfer heat, its resistance can be calculated using Ohm's Law, and it draws power when initially switched on.

Nichrome wire is used as a heating element in heaters due to its high resistance to electric current, which causes it to heat up and transfer that heat to its surroundings. When electricity flows through a conductor like nichrome, heat is generated as a result of the resistance to the flow of electrons.

The resistance of the Nichrome wire can be calculated using Ohm's Law, knowing the power output and voltage supplied. Additionally, the length of the Nichrome wire needed can be determined based on its cross-sectional area and operating temperature.

When first switched on, the Nichrome wire heating element will draw a certain power as it starts to heat up until it reaches its operating temperature and stabilizes.

Answer:

c. Alkaline earth metals

Explanation:

The person's legs exert a force on his torso during deceleration equivalent to the work they must do to bring his torso's kinetic energy to zero. This force can be calculated using the relationship between work and energy and the mass, height of the fall, and distance over which the force is applied.

To find the magnitude of the average force exerted on the person's torso by his legs during deceleration, we need to use the relationship between work and energy, specifically the work-energy theorem. This theorem states that the work done on an object is equal to the change in its kinetic energy.

When the person jumps from the roof, he gains kinetic energy equal to the gravitational potential energy he loses, which can be calculated as mgΔh, where m is the mass of the torso (45 kg), g is the acceleration due to gravity (9.8 m/s²), and Δh is the height of the fall (3.5 m).

This kinetic energy becomes zero when the person's legs decelerate his torso to a stop. The work done by the legs in this process is therefore equal to the kinetic energy the torso had initially, which gives a force F according to the equation W = F⋅d, where W is the work and d is the distance over which the force is applied (0.71 m).

Solving for F we find the average force exerted by his legs during deceleration.

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The problem is about calculating force exerted on a person's torso when he jumps from a certain height. Initially the gravitational potential energy of the person is converted to kinetic energy, and then dissipated as work done when he bends his knees to decelerate. The force can be calculated by first calculating deceleration and then using F=ma, where m is the mass of the torso and a is the deceleration.

The subject of your question involves calculating the force exerted on a person's torso by his legs during a jump from a certain height. This is a physics problem related to gravitational potential energy, kinetic energy, and work. Initially, when the person is on top of the roof, the entire energy of the system is gravitational potential energy which can be calculated by the formula: PE = mgh. When the person jumps and hits the ground, this energy transforms into kinetic energy. However, this kinetic energy is not immediately dissipated. Instead, the person bends their knees and decelerates over a certain distance, which implies that the energy is dissipated over a certain period of time or work done. This work done can be calculated by the formula: W = -KE = mgh. The force can therefore be calculated using the formula: F = ma, where a is the deceleration. The deceleration can be obtained from the relation between displacement, initial velocity, final velocity, and acceleration which is (final velocity^2) = (initial velocity^2) + 2*a*d. Here, initial velocity is the velocity with which the person hits the ground and the final velocity is zero as the person completely stops and 'd' stands for the distance over which the person decelerates.  Once 'a' is calculated, it can be substituted into the equation F = ma to find the force.

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Yo sup??

To solve this question we must know that

P=VI

V=120 V

I=2 A

Therefore by using the above formula we get

P=120*2

=240 J

Hope this helps.

Answer: 240watt

Explanation:

V = 120 V

I = 2A

P = IV = 2 x 120

P = 240watt

Final answer:

The question relates to how white light spreads out or reflects on a white paper and a mirror, governed by the law of reflection in Physics. Diffused light allows a sheet of paper to be visible from multiple angles, while a mirror reflects light at specific angles based on its smooth surface.

Explanation:

The question pertains to the law of reflection in Physics, looking specifically at how light behaves when shining on different surfaces. When a beam of white light shines onto a sheet of white paper, the light is scattered, or diffused, due to the roughness of the paper's surface. This scattering allows the paper to be seen from various angles. In contrast, when the identical beam shines onto a mirror, the light is reflected because of the mirror's smooth surface.

The reflection adheres to the law of reflection, which states that the angle of reflection equals the angle of incidence (θr = θi). White light on yellow paper and yellow light on white paper will result in color changes due to the colors being absorbed or reflected, whereas red and green lights on white paper may combine to produce a different color perception depending on the superposition of the lights.

Answer:

Protostars

Explanation:

Most stars originally form from protostars.

Answer:

A reaction time is something that measures the amount of time for you to respond to a stimulus. For an example the average human reaction time for a visual stimulus is 0.25 seconds, 0.17 seconds for a audio stimulus and 0.15 seconds for a touch stimulus.

Explanation:

Stimulus - A thing or event that evokes a specific functional reaction in an organ or tissue

Answer:5990 kj

Explanation:

Answer:

In a positive ion, the number of protons is larger than the number of electrons.

In a negative ion, the number of protons is smaller than the number of electrons.

Explanation:

Each proton carries a positive charge of one unit.

Each elec in tron carries a negative charge of one unit.

In an atom, there are as many protons as electrons. Hence, they are neutral.

However, in a positive ion, there are less negative charge than positive charge. Hence the net charge is positive. That also means that there are fewer negatively-charged electrons than positively-charged protons.

Similarly, in a negative ion, there are more negative charge than positive charge. Hence the net charge is negative. That also means that there are more negatively-charged electrons than positively-charged protons.

Answer:

A.  It provides resources like food and shelter to support life. ( on edmentum at least.)

"the fuel in a nuclear power station is Uranium 235"​

Explanation:

Answer:

In a series circuit, adding more resistors increases total resistance and thus lowers current.

Answer:

To find the total resistance of the circuit:

They are 2 ways to get that ( you can use both methods for 1 exercise)

1- If resistances are series, just add together .

Rt = R1 + R2

2 If are parallel, do the same thing but the inverse of each resistance .

Rt =1/R1 + 1/R2

Final answer:

The total resistance in a circuit with series and parallel components can be calculated by summing the resistances in series and using the reciprocal rule for resistors in parallel, before combining the two results.

Explanation:

To calculate the total resistance in a circuit, one must know the configuration of the resistors, whether they are in series, parallel, or a combination of both. The student's question suggests they are dealing with a combination of series and parallel circuits, requiring different approaches for each section.

For resistors in series, the total resistance, Rtot, is the sum of all individual resistances. So, if we have resistors R1, R2, and R3 in series, the Rtot would simply be R1 + R2 + R3.

In a parallel configuration, the total resistance, Rp, is found using the formula 1/Rp = 1/R2 + 1/R3. After calculating Rp, if this parallel combination is in series with another resistor R1, then the overall total resistance is Rtot = R1 + Rp. To get the value of Rp, one would calculate the reciprocal of the sum of the reciprocals of the individual resistances in parallel, and then take the reciprocal of that result.

By following these rules, and using the correct units and values given for the resistors, students can accurately determine the total resistance of various circuit configurations.

Answer:

I=1A

Explanation:

In parallel combination voltage is same

In R1

V=IR

V=2×4

V=8V

In R2

V=IR

I=V/R

I=8/8

I=1A

Answer:

Velocity = 4.33[m/s]

Explanation:

The total energy or mechanical energy is the sum of the potential energy plus the kinetic energy, as it is known the velocity and the height, we can determine the total energy.

[tex]E_{M}=E_{p} + E_{k} \\E_{p} = potential energy [J]\\E_{k} = kinetic energy [J]\\where:\\E_{p} =m*g*h\\E_{p} = 4*9.81*0.5=19.62[J]\\E_{k}=\frac{1}{2} *m*v^{2} \\E_{k}=\frac{1}{2} *4*(3)^{2} \\E_{k}=18[J]\\Therefore\\E_{M} =18+19.62\\E_{M}=37.62[J][/tex]

All this energy will become kinetic energy and we can find the velocity.

[tex]37.62=\frac{1}{2} *m*v^{2} \\v=\sqrt{\frac{37.62*2}{4} } \\v=4.33[m/s][/tex]

Answer:

GRAVITY

Explanation:

Newtons third law, "Gravity" attracts all objects to each other.

80 joule is momentarily stored in each spring

Solution:

Given that,

The coil springs on a car's suspension have a value of k = 64000 N/m

When the  car strikes a bump the springs briefly compress by 5.0 cm (.05 m)

By compressing the spring, we apply a force over a distance

As a result we have done work on the spring

Doing work means that we have transferred energy to spring in form of elastic potential

Therefore,

k = 64000 N/m

x = 0.05m

The elastic potential energy is given as:

[tex]PE = \frac{1}{2}kx^2[/tex]

Where, "k" is the spring constant and "x" is the displacement

[tex]PE = \frac{1}{2} \times 64000 \times 0.05^2\\\\PE = 32000 \times 0.0025\\\\PE = 80[/tex]

Thus 80 joule is momentarily stored in each spring

The energy momentarily stored in each spring is[tex]\(\frac{1}{2} \times 64000 \times (0.05)^2 = 80\) joules.[/tex]

To find the energy stored in a spring when it is compressed, one can use the formula for elastic potential energy, which is given by:

[tex]\[ U = \frac{1}{2} k x^2 \][/tex]

where U is the elastic potential energy, k is the spring constant, and x is the compression or extension of the spring from its equilibrium position.

Given that the spring constant k is 64000 N/m and the compression x is 5.0 cm (which is 0.05 m when converted to meters), we can substitute these values into the formula:

[tex]\[ U = \frac{1}{2} \times 64000 \times (0.05)^2 \][/tex]

[tex]\[ U = \frac{1}{2} \times 64000 \times 0.0025 \][/tex]

[tex]\[ U = 32000 \times 0.0025 \][/tex]

[tex]\[ U = 80 \][/tex]

Therefore, the energy momentarily stored in each spring is 80 joules.

Answer:

Friction force

Explanation:

Friction force is a force that opposes a motion from moving but friction may seem a bad thing but it is very useful for writting and for other things. please give me a like and thank me.

The force that opposes motion between two surfaces is known as friction. It depends on the types of materials and surfaces in contact. There are four types of friction: Static, Sliding, Rolling, and Fluid, and each one has practical applications in our daily lives.

The force that opposes motion between two surfaces is known as friction in physics. Friction is everywhere in our daily lives. It's the force that allows us to walk, ride a bike, or even hold objects in our hands. The amount of friction between two surfaces is dependent on the type of materials in contact and how rough the surfaces are. For example, ice has less friction than gravel.

There are four types of friction: Static, Sliding, Rolling, and Fluid. The friction that opposes motion between two stationary objects (when you try to slide a heavy box, for instance) is known as static friction. When the objects are set in motion, the friction is known as sliding friction. A moving object over the surface like a wheel over the road experiences rolling friction. Fluid friction refers to the resistance between layers within a viscous fluid or when the fluid is moving over a surface. Each type of friction has important practical applications and implications in our day-to-day life.

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Answer:

simplifying the circuit into groups of series and parallel circuits.

Explanation:

Answer: 3g/cm3

Explanation:

Mass = 8g

Volume = 2.8325 cm^3.

Density = Mass / volume

Density = 8/2.8325 = 3g/cm3

The force exerted by the filled grocery bag when it is lifted with an acceleration of 5.0 m/s² would be 294 N. As this is higher than the maximum force the bag can withstand (250 N), the bag would rip, and the groceries would not stay within it.

The maximum force that a grocery bag can withstand without ripping is 250 N. Suppose that the bag is filled with 20 kg of groceries and lifted with an acceleration of 5.0 m/s²; we need to verify if the groceries stay in the bag. The force exerted by the bag, according to Newton's second law (F=ma), will be the mass of the groceries (m) times the gravitational acceleration (g) plus the additional acceleration due to lifting (a). Here, g=9.8 m/s², and the bag is lifted with a=5 m/s².

The force exerted by the filled grocery bag will be F=(m*(g+a))= 20 kg*(9.8 m/s²+5.0 m/s²)= 294 N.

Since 294 N is greater than the maximum force the bag can withstand (250 N), the bag will rip, and the groceries will not stay in the bag if the bag is lifted with an acceleration of 5.0 m/s².

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The correct option is option A.

According to the universal gas equation, the product of the pressure and volume of a gas is directly proportional to the product of the number of moles of gas and the absolute temperature of the gas.

So PV is proportional to nT.

Here, it's said that the temperature of the gas is constant. And inside a tube, the volume of the gas remains constant.

So the pressure of the gas will be directly proportional to the number of moles of gas. So as the number of moles of the gas rises, the pressure of the gas also rises. So, with addition of more gas into tyre, the pressure of gas will also increase.

Answer:

a

Explanation:

gradpoint gang

Answer:

6 bub

Explanation:

Lifting a heavy box and placing it on a table increases its potential energy due to the work done against gravity. The box remains stationary with this added potential energy. If the box were to fall, this potential energy would be converted into kinetic energy as it accelerates towards the ground.

When you lift an object such as a heavy box and place it on a table, if the box remains stationary, it means that you have changed its energy state. Specifically, you have increased its potential energy. Potential energy is the energy stored in an object as a result of its position or height. For example, in Physics, lifting a 20 kg box of books through a vertical distance of 2m would involve an energy expenditure of approximately 400 J, signifying that the box gained 400 J of potential energy. This energy transfer occurs because of the work done against gravity: applying a force to lift the object off the ground increases its potential energy. Once the object is released, if it falls, the stored potential energy is converted into kinetic energy as it accelerates towards the ground due to the force of gravity.

It is important to note that while lifting the object, if it is done slowly so that the box's speed does not change significantly, the kinetic energy of the object remains constant (nearly zero if lifted slowly enough), although its potential energy increases. This concept is exemplified when an object is lifted using a device powered by chemical energy, such as a gasoline engine; the chemical energy is converted into gravitational energy, which is then stored in the object as potential energy. When it comes to work and energy, the work done on an object adds to its total energy. If that work is done to lift an object against the force of gravity, it is stored as potential energy.

Answer:

Resistor

Explanation:

Resistors are measured in ohms . So one ohm is the amount of resistance that opposes current flow from one part of a circuit to another. The voltage v is directly proportional to the current I so , V= IR

Resistance R =

voltage v/ current I