please someone help i don't know how to do this

The time taken to reach a velocity of 8 m/s, west if her acceleration is 2 m/s is 3 seconds

Given,

Velocity of Keiko's skateboard = 2 m/s

Velocity to reach = 8 m/s

Acceleration = 2 m/s²

Velocity is known to be the total displacement that occurred in a particular given time.

It is a vector quantity that has both magnitude and direction.

By the 1st equation of motion regarding velocities,

v = u + at ...........(1)

where,

v = final velocity = 8 m/s

u = initial velocity  = 2 m/s

t = time = ?

a = acceleration = 2 m/s²

Now put all the given values in the above equation 1, we get:

8 m/s = 2m/s + (2 m/s²)t

t = 3 seconds

Therefore, using the velocities, we got the the time taken will be 3 seconds.

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This collision violates conservation of both energy and momentum i.e, third option is correct.

According to the law of conservation of momentum, when two bodies collide their total momentum and energy before and after collision are equal.

According to the law of conservation of energy, energy can neither be created nor destroyed. However, it can be transformed from one form to another. It is also known as the first law of thermodynamics.

Given that, the two bodies move with same velocities after collision, means that the law has not been violated since, momentum = mass*velocity (where mass is said to be constant)

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The recoil speed of the flatcar is0.5 m/s.

The cannon's momentum equals the flatcar's momentum according to Newton's third law of motion.

mv = MV........................ Equation 1:

where m is the cannon's mass, v is its velocity, and m is the flatcar's mass, v is its velocity.

Assign V as the subject of the equation V = mv/M... Equation 2

Given: M = 1000 kg

m = 10 kg,

and v = 50 m/s

Replace with V = 1050/1000 V = 500/1000

V = 0.5 m/s in equation 2.

Consequently, the flatcar's speed is equal to 0.5 meters per second.

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The current through the long wire is 20A.

What is a magnetic field in simple terms?

The magnetic field is the area around a magnet in which the effect of magnetism is felt. We use the magnetic field as a tool to describe how the magnetic force is distributed in the space around and within something magnetic in nature.

What causes a magnetic field?

Magnetism is caused by the motion of electric charges. Every substance is made up of tiny units called atoms. Each atom has electrons, particles that carry electric charges. Spinning like tops, the electrons circle the nucleus, or core, of an atom.

How do you find current in a wire in a magnetic field?

The strength of a magnetic field, , some distance  away from a straight wire carrying a current, , can be found using the equation  =   2  , where  is a constant known as “the permeability of free space”

What happens when a wire with a current is placed in a magnetic field?

The wire will bend away from the poles of the magnet.

[tex]i=\frac{2\pi RB}{m_{0}}[/tex]

Given : [tex]R=0.50m, B=8*10^{-6}[/tex]

[tex]i=\frac{2\pi *0.50*8*10^{-6}}{4\pi *10^{-7}}[/tex]

[tex]i=20A[/tex]

Thus, the current flowing in the wire is 20A.

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The kinetic energy of the bullet when it left the gun barrel is 1000J.

We know that ,

K.E. = F d

where, K.E. = kinetic energy

F = force

d = distance

Given, F = 1* 10^4 N

          d = 10cm = 0.1 m

Putting these values in above equation we get,

K.E. = 1000J

So the kinetic energy of the bullet when it left the gun barrel is 1000J.

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The emf created around the wooden loop is equivalent to the emf generated around the wire loop if the loops are moved precisely the same distance from and closer to the magnets.

Give an explanation about EMF.

The electric potential created by either modifying the magnetic field or by an electrochemical cell is known as electromotive force (emf).

Due to the fact that Faraday's law is independent of the material and only considers how the flux is changing, the emf produced around the wooden loop is equivalent to the emf produced around the wire loop. Due to the fact that the loop material moves close to the end of the bar magnet, modifying the magnetic flux through the loop, even though it is not a part of the magnetic flux expression, an emf is nevertheless produced.

Hence, the answer is the emf created around the wooden loop is equivalent to the emf generated around the wire loop if the loops are moved precisely the same distance from and closer to the magnets.

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Answer:

E = V q      energy attained by charge q thru potential energy V

E = 1/2 m v^2      kinetic energy of charge q

1/2 m v^2 = V q        equating energy attained

v^2 = 2 V q / m

v = (2 V q / m)^1/2

The final  speed is proportional to the square roots of V, q, and inverse of square root of m.

The voltage drop across resistors r2 in volts is 6.6 volts.

Resistor is defined as an electrical component that regulates voltage and temperature. Resistors are frequently employed in electronic circuits to reduce current flow, divide voltages, impede transmission signals, and bias active parts. The resistor controls the electron flow to prevent overly rapid current from damaging the breadboard, wires, battery,

The Voltage drop can be calculated as

Give voltage of battery = 113 V

R2 has current = 1.9 A

And resistance = 4.7 ohms

Voltage = 1.9 + 4.7

             = 6.6 V

Thus, the voltage drop across resistors r2 in volts is 6.6 volts.

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Applying the Conservation of Energy, the point above the starting point of the pebble will fly is 12.8 m

Given Parameters:

Mass of the pebble (m) = 51 g

Spring Constant (k) = 320 N/m

Extension (x) = 0.20 m

Law Of Conservation Of Energy:

According to the rule of conservation of energy, energy cannot be created or destroyed. Energy doesn't evaporate when it is used by people.

Within a specific frame of reference, the total energy of an isolated system either remains constant or is conserved.

According to the law of conservation of energy

Kinetic Energy is equal to potential Energy,

[tex](1/2)kx^2 = mgh\\\\h = (kx^2) / (2mg)= [(320 N/m)(0.20m)^2] / [2(0.051kg)(9.8 m/s^2)]= 12.8 m[/tex]

Thus, The point above the starting point of the pebble will fly is 12.8 m.

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The maximum speed at which a car can safely travel around a circular track of radius 55. 0 m is 10.84  m/s

Any object is drawn toward the center of a curved surface by a centripetal force. Imagine that you are a yo-yo being spun. The yo-yo is set in motion by your arm movement, and as you twirl it, the tension of the string keeps it spinning.

Given : r=30 m            

μ=0.4                  

g=9.8m/s

2The maximum speed        

v max =μgr= 0.4×9.8×30 =10.84  m/s

A force known as centripetal force keeps things moving in a circular motion. The object will keep rotating in a circle as long as the centripetal force persists and all other forces are equally balanced. One object that moves in a circle as a result of centripetal force is a yo-yo.

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The answer is A. Metallic bonding occurs when a negative metallic ion is attracted to a positive metallic ion through electrostatic attraction

Metallic bonds are formed when the charge is spread over a larger distance than the size of single atoms in solids. Metallic bonding is a chemical bonding that arises from the attractive electrostatic force between conduction electrons (in the form of an electron cloud of delocalized electrons) and positively charged metal ions. It may be described as the sharing of free electrons among a structure of positively charged ions (cations). Metallic bonding is not the only type of chemical bonding a metal can exhibit, even as a pure substance.

Metallic bonding occurs when you have a metal in a solid or liquid state. The s and p valence electrons of metals are loosely held. They leave their “own” metal atoms. This forms a "sea" of electrons that surrounds the metal cations. The electrons are free to move throughout this electron sea. A strong metallic bond will be the result of more delocalized electrons, which causes the effective nuclear charge on electrons on the cation to increase, in effect making the size of the cation smaller.

Metallic bonds are strong and require a great deal of energy to break, and therefore metals have high melting and boiling points. A metallic bonding theory must explain how so much bonding can occur with such few electrons (since metals are located on the left side of the periodic table and do not have many electrons in their valence shells). The theory must also account for all of a metal's unique chemical and physical properties.

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A circular loop of wire with a radius of 13.0 cm and oriented in the horizontal XY-plane is located in a region of the uniform magnetic field. A field of 1.7 T is directed along the positive z-direction, which is upward. A) If the loop is removed from the field region in a time interval of 2.9 ms,

The average emf that will be induced in the wire loop during the extraction process=

e =(pi) r^2B/t

e = pi*169*10^-4*1.7/(2.9*10^-3) = 31.12 V

In classical geometry, a radius of a circle or sphere is any of the line segments from its middle to its perimeter, and in greater present-day usage, it is also their length. The call comes from the latin radius, which means ray but additionally, the spoke of a chariot wheel.

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The efficiency of the lever will be 62%

Efficiency is the ratio of the work performed by a machine to the total energy expended or heat consumed.

Efficiency refers to how close we can get to a particular outcome of the given input with as much less wastage as possible. Efficiency is the ability to minimise wasting materials, efforts, energy and time in performing something or producing the desired result.

The ratio of energy transferred to a useful form compared to the total energy supplied initially is called the efficiency of the device.

Efficiency (%) = (work output/work input) x 100%

work output = mgh

work input = 10,000J

Efficiency (%) = (35 x 18 x 9.8/10,000) x 100

Efficiency (%) = 0.62 x 100

Efficiency (%) = 62%

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Five times per second is the typical frequency at which another pendulum swings back and forth. 2S

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The useful energy the machine will generate in 15minutes is 81000J

The efficiency of a machine indicates how well its input energy is converted to useful output energy or work. It is a major factor in the usefulness of a machine and is the fraction or percentage of the output divided by the input.

Therefore the efficiency of a machine is given as Energy output/ energy input ×100 or power output/ power input ×100

let the power output be x

therefore 18=( x/500)×100

100x = 18×500

x= 18×500/100= 90J/s

Energy = power ×time

in 15minutes = 15×60s, the machine will generate energy of 90×15×60= 81000J

Therefore the machine will generate a useful energy of 81000J

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Pendulum length must be made for it to keep perfect time of 100 or 0.0167 % or 0.017 % nearly.

Time is the  measure of to  non-stop, consistent change by  in our surroundings, or it is  usually from a specific to  viewpoint.

Total number of seconds in a normal day is 24×60×60 = 86400 seconds

We know that time period of pendulum is

T= 2π √l/g

Then we use fractional error method

∆T/T = 1/2 ( ∆l /l )

Here l is length of pendulum string

So 7.2/86400 = 1/2 ( ∆l/l)

∆l/l = 0.000167

So percentage change is

∆l/l *100 or 0.0167 % or 0.017 % nearly.

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The spring constant of this elastic cord is 562.64 Nm.The frequency of the motion with the 210 N is 0.817Hz.

Elastic cord is a fairly versatile stretchy rope. it is small diameter makes it ideal for indoor craft makes use of and light duty strapping. Use this elastic string for sewing initiatives, scrapbooking, and kids' crafts.

Calculation:-

Spring constant K = f/x

= 75/0.61 - L

= 75/0.61 - 0.4767

= 562.64 Nm

Frequency when 210 N is hanging is

extension X = 0.85 -L

= 0.87 - 0.4767

= 0.3733

Frequency = 1/2π√g/X

= 1/2π √9.8/0.3733

= 0.816 Hz.

The free movement of a frame with appreciate to time is called motion. for example-the fan, the dirt falling from the carpet, the water that flows from the tap, a ball rolling around, a shifting car etc. Even the universe is in chronic motion.

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The rate constant for the nuclide is 0.08.

We know that rate of first order reaction is given by: [tex]kt = 2.303 * log(R'/R)[/tex]

where k = rate of reaction

           t = time = 23 minutes

           R' = initial mass = 12.9 grams

           R = final mass = 2.04 grams

Putting these values in above equation we get k = 0.08.

i.e. the rate constant for the nuclide is 0.08.

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The answer is (b), meaning that we haven't been looking for planets so at distances for long enough.

(Astronomy) The solar system is made up of the sun and the objects gravitationally attracted to it, such as the planets Mercury, Venus, Mars, Mars, Octavian, Saturn, Uranus, and Neptune, as well as the minor planets Eris, Pluto, and Ceres.

The world sustains us and gives us the resources we require. Last but not least, experts claim that if our planet disappeared, we and everything else on the world would have died. The one and only planet capable of supporting life is Earth.

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Velocity of golf ball after collision with golf club using law of conservation of momentum is 65.21 m/s

What is momentum ?

Momentum seem to be directly dependent on the value of mass as well as velocity of the object in the direction of motion.  it is quantified by "mass velocity". Since mass is a scalar quantity but velocity is a vector, momentum is a vector quantity.

From the given information-

mass of golf club = 200 g

mass golf ball = 46 g

velocity of club before collision = 55 m/s

velocity club after collision =40 m/s

velocity of golf ball before collision = 0 m/s

You need to use conservation of momentum here.

momentum = mass x velocity

Prior to impact, the golf club has a momentum of 0.200 kg * 55 m/s = 11.00 kg m/s.

The ball's not moving before impact, so it has a momentum of zero. Therefore the total momentum before impact will be 11.00 kg m/s. Conservation of momentum dictates the total momentum of the two objects after impact will also be 11.00 kg m/s.

We know the speed of the club after the impact, so the momentum of the club after impqact is 0.200 kg * 40 m/s =8 kg m/s.

So the momentum of the ball must be 11.00 kg m/s - 8 kg m/s = 3 kg m/s, and dividing by the mass of the ball (0.046 kg) gives the speed of the ball, 65.217 m/s

Velocity of golf ball after collision wit golf club is 65.21 m/s

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The resistance of the second wire will be 10 ω.

What is resistance?
Electrical resistance, or resistance to electricity, is a force that opposes the flow of current. It acts as a gauge for the difficulty of current flow in this way. Ohms (Ω) are used to express resistance values. Electricity would then flow from high to low when two terminals have an electron differential. That flow is countered by resistance. The current decreases as resistance increases. On the other hand, the current increases as the resistance decreases. Resistance could be calculated as a number using the circuit's voltage and current.

The resistance of a wire is inversely proportional to its length, so the second wire, which is 10 meters long, will have a resistance that is 10 times less than the first wire, which is 100 meters long. The resistance of the second wire will be 100 ω ÷ 10 = 10 ω.

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The maximum velocities in the two cases related are Vmax,2 = 2 Vmax,1

Simple harmonic motion :

In physics, simple harmonic motion is the repeated back-and-forth  motion through an equilibrium, or center, position so that the maximum displacement on one side of this position is equal to the maximum displacement on the other. Each whole vibration occurs at the same time interval.

Complete question:

In the two cases shown the mass and the spring are identical but the amplitude of the simple harmonic motion is twice as big in Case 2 as in Case 1.

1)How are the maximum velocities in the two cases related?

Vmax,2 = Vmax,1

Vmax,2 = 2 Vmax,1

Vmax,2 = 4 Vmax,1

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If quasars are located at the distances that the majority of astronomers think they are, then their luminosities must equal the sum of one hundred trillion (1014) Suns.

Something's luminosity is determined by how much light it emits or reflects. A big, sparkling diamond's brightness is its most distinguishing feature. You might talk about the luminosity of an energetic and vibrant oil painting or be in awe of the luminosity of a spectacular sunset.

Small (2–3 point) training benefits are obtained via lumosity training. If you exercise for 12 and a half hours over several weeks, you can enhance your IQ, working memory, and other cognitive abilities by about 2-3 points.

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Given details :

a)  For this exercise we use the equation for thin lenses

              1 / f = 1 / p + 1 / q

where f is the focal length, p the distance to the object and q the distance to the image

              1 / f = 1 / 8.00 + 1/2

              1 / f = 0.625 cm⁻¹

power is the inverse of the focal length in meters

             P = 1 / f [m]

             P = 0.625

             P = 62.5 diopter

b)  the size of the image

            m = - p / q

            m = - 2 / 8.00

            m = -0.25 X

if we assume that the object is right

           m = h´ / h

           h´ = m h

           h´ = -0.25 x 2

           h´ = -0.5 mm

if the height of the object h is straight the image and inverted

c) if the object were at p = 25.0 cm

          m = - 2/25

          m = -0.08

            h´ = -0.08 x 2

            h´ = -0.16 mm

the image would be much smaller

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The work done by the gas is 190,000 J.

What is work?
Work in physics is the energy that is transferred to or from a object when a force is applied along a displacement. In its simplest form, it equals the product of the force's magnitude and the distance travelled for a constant force directed in the same direction as the motion. When a force is applied, it is said to have a component that moves the point of application, or it is said to have positive work. If the component of a force at the point of application is in the opposite direction of the displacement, the force is said to do negative work.

The work done by the gas can be calculated using the equation W = P∆V. In this equation, P represents the constant pressure of 400 kPa, ∆V is the change in volume, and W is the work done by the gas.

Since the volume of the gas changed from 900 cm3 to 425 cm3, the change in volume is ∆V = 900 cm3 - 425 cm3 = 475 cm3. Plugging this into the equation above, we get W = 400 kPa x 475 cm3 = 190,000 J.

Therefore, the work done by the gas is 190,000 J.

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The frequency is 5 x 10^14 Hz, the speed of light in the medium is 2 x 10 m/s and the wavelength is

4 x 10^-7 m

Given that,

Wavelength X = 600 nm

Refractive index n = 1.5

We know that,

The frequency is the ratio of the speed of light and wavelength of the light.

f = c/λ

f = 3 x 10^8/600 × 10^-9

f = 5 x 10^14 Hz

The speed in the medium is the ratio of the speed of the light in the vacuum and the refractive index.

n = c/v

1.5 = 3 x 10^8/υ

v = 2 × 10^8 m/s

The wave length is the ratio of the speed of the light in the medium and frequency.

λ = v/f

λ = 2 × 10^8/5 x 10^14

λ = 4 × 10^-7 m

Hence, The frequency is 5 x 10^14 Hz, the speed of light in the medium is 2 x 10^8 m/s and the wavelength is 4 x 10^-7 m

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The pressure in the connecting pipe is 88 pa.

Stress is the pressure applied perpendicular to the floor of an object according to unit place over which that force is sent. Gauge strain is the strain relative to the ambient pressure. diverse gadgets are used to explicit strain.

Calculation:-

radius of pipe = 1.5 cm

speed = 5 m/s

The speed is increases to 11.0 m/s

density of the fluid = 900 kg kg/m³

Pressure = 1.30 × 10⁵ N/m²

The pressure in the connecting pipe in pa = ρdv/dl

                                                                        = 88 pa.

Stress is defined because the bodily pressure exerted on an item. The force applied is perpendicular to the surface of objects in step with unit place. The primary components for strain is F/A (force in keeping with unit location). Unit of pressure is Pascals (Pa). forms of Pressures are Absolute, Atmospheric, Differential, and Gauge pressure.

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(a) Formulae for magnification (m) = distance of image/image of object

                                             =.025/3.2 = 0.00781

so, magnification of eye = 0.00781

now. m = image size / actual size

so, image size = actual size x m

                        = 1.7 x 0.00781

                        = 0.0132 m

(b) similarly, in this case the size of the image can be calculated as follows:

m = distance of image/image of object = 0.00595

image size = actual size x m = 0.0101

What is magnification?

Magnification in physics can be defined as the ratio of size of the image to the size of the object. Magnification in simple terms means enlargement in the size of the image of an object.

It can be denoted by the formulae:

[tex]magnification = \frac{size of the image}{size of the object}[/tex]

It has no SI unit.

Why Magnification has no SI unit?

It has no SI unit because it is a ratio of length.

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Saturn, Uranus, and Neptune

The reason is that  more mass is added interior to those planets' orbits. With a greater interior mass, Saturn, Uranus, and Neptune will experience a larger gravitational force and an increased orbital speed.

A planet's orbital speed changes, depending on how far it is from the Sun. The closer a planet is to the Sun, the stronger the Sun's gravitational pull on it, and the faster the planet moves. The farther   from the Sun, the weaker the Sun's gravitational pull, and the slower it moves in its orbit.

As seen in the equation v = SQRT(G * Mcentral / R), the mass of the central body (earth) and the radius of the orbit affect orbital speed.

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15.38 % is pt/pi including the background correction.

The greatest deviation from equilibrium of a point on either a vibrating body or wave in terms of displacement or distance traveled. It is similar to the half-length of the vibration path.

Briefing :

Background [tex]=13mv[/tex]

corrected signal [tex]= 91mv - 13 mv = 78mv[/tex]

with attenuator[tex]=25mv - 13mv = 12 mv[/tex]

[tex]\frac{P_{t} }{P_{i} } = \frac{12}{78} . 100[/tex]

[tex]= 15.38 %[/tex] %

Therefore , the pt/pi is 15.38 %

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