A person can see objects clearly only if they are between 0.6 m and 4 m from her eyes. Her optometrist prescribes bifocals that enable her to see distant objects through the top half of the lenses and read papers at a distance of 0.25 m through the lower half. What are the respective powers of the top and bottom lenses?a. -0.25 dB (top lens); +5.7 dB (bottom lens)b. +2.3 dB (top lens); -3.3 dB (bottom lens)c. +4 dB (top lens); -1.7 dB (bottom lens)d. -5.7 dB (top lens); +0.25 dB (bottom lens)e. -0.25 dB (top lens); +2.3 dB (bottom lens)

The half-life of polonium-218 if a sample decays from 55. 4 g to 31. 7 g in 2. 50 minutes is 3.5 minutes.

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

Where , k = rate of reaction

             t= time = 2.5 minutes

             R= final amount = 31.7g

             R'= initial amount = 55.4g

Putting these values in above equation we get k = 0.22

Now half life of a first order reaction is given by: 0.693/k

Putting k= 0.22 , we get half life = 3.5 minutes.

So the half-life of polonium-218 if a sample decays from 55. 4 g to 31. 7 g in 2. 50 minutes is 3.5 minutes.

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The spring constant of the spring is 6.66 N/m.

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

An external force is an agent that has the power to alter the resting or moving condition of a body. It has a direction and a magnitude.

The rotational speed of the 90 g = 0.09 kg mass is: ω = 90 rpm

= 90×2π/60 radian/second.

 = 3π radian/second.

So centripetal force acting on the spring = mω²r

This causes the spring to stretch to a length of 12 cm = 0.12 m.

Hence, spring constant: k = mω²r/0.12 =  0.09×(3π)²×0.10/0.12 N/m = 6.66 N/m.

Hence, the spring constant of the spring is 6.66 N/m.

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The average angular acceleration of Ferris wheel is 0.368m/s².

ω=1.9rad/s

α=4.9rad

To find angular acceleration.

[tex]w^2=2\alpha s[/tex]

To find α:-

[tex]\alpha =\frac{w^2}{2s}[/tex]

=1.9 x 1.9/9.8

=0.368m/s²

To find angular acceleration-

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In an oscillator consisting of a spring and a block, the amount of kinetic energy reaches maximum when: A. The block passes over the equilibrium point.

In Science, kinetic energy can be defined as a type of energy that's possessed by a physical object or body, especially due to its motion or a change in velocity (acceleration).

This ultimately implies that, a physical object or body would gain more of kinetic energy as it falls back toward the Earth because it is in motion.

In an experiment that is based on an oscillator using both a spring and a block, the amount of kinetic energy that is possessed by the block would reach maximum when it passes over the equilibrium point.

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Complete Question:

In an oscillator consisting of a spring and a block, the amount of kinetic energy reaches maximum when:

The block passes over the equilibrium point.

The block is at maximum positive displacement from the equilibrium point.

The spring's extension is half of the amplitude of oscillation.

The spring is at maximum compression.

None of these.

The magnitude and direction of the minimum magnetic field that will keep the particle moving in the earth’s gravitational field in the same horizontal, northward direction is 1.911 Tesla.

Velocity v = 4×[tex]10^{4}[/tex]

Charge q = 2.5 × [tex]10^{-8}[/tex]

Mass of particle m= 0.195 g = 0.195 × [tex]10^{-3}[/tex] kg

Using the concept of Lorentz force

mg=Bvq

B = mg/vq

Substituting the values

B= 0.195 × [tex]10^{-3}[/tex] × 9.8/4×[tex]10^{4}[/tex]×2.5×[tex]10^{-8}[/tex]

B= 1.911 Tesla

Therefore, To produce upward force, using right hand value and taking particle in negative charge then the magnetic field has to be point in eastwards.

What is gravitational field?

In physics, a gravitational field is a model used to describe the effect of one massive object spreading out in space around it and creating a force on another massive object. Gravitational fields are used to describe gravitational phenomena and are measured in Newtons per kilogram.

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Two metres of rope must be raised in order to move the burden every metre.

Explain why two metres of rope should be raised.

Assuming no dissipative forces are at work over the rope.

The effort is used to draw upward on the rope's free end while the load is hung from the pulley block. The effort required is just half the amount of the load because the load is now suspended from two ropes, each of which is bearing half of the weight.

Hence, two metres of rope must be raised in order to move the burden every metre.

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It can hear the two speakers' beats because of the frequency of 30 Hz. Consider driving one speaker at 590 Hz and another at 560 Hz.

The quantity of observations that take place during a specific predetermined timeframe is the frequency of the a class interval. Therefore, if 20 individuals between the ages of 5 and 9 are found in the data from our study, the frequency again for 5–9 age range is 20.

The temporal rate of evolution seen in oscillatory & periodic events, such as vibrations, speech recordings (sound), radio frequencies, and light, is specified by the frequency, an essential parameter in science and engineering.

Beat frequency f = f₂ - f₁

F₂ = 590 Hz

F₁ = 560 Hz

f = 590 - 560

f = 30 Hz

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Parabolic Up. Since the force is in the y-direction, the particle will continue to move at a constant speed in the x-direction and accelerate in the y-direction. This creates a parabolic path around y-axis.

Force is the power that changes the motion of an item. A force can purpose an object with mass to alternate its pace. Pressure also can be described intuitively as a push or a pull. A force has both value and path, making it a vector quantity.

Pressure is a push or a pull and it affects us in our daily lives because, without force, people might not be capable of open and near stuff or lifting up their arms or legs.

Variety of Forces :

* Muscular Forces, muscular tissues feature to produce an ensuing force which is referred to as 'muscular force'.

* Frictional Forces, while an item modifications its national motion, 'frictional pressure' acts upon it.

* Carried out pressure.

* Tension force.

* Spring force.

* Gravitational pressure.

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While changing direction, the object will continue to move at the same speed.

In way of comparison to kinetic energy, which defines the course and speed of an object's moving, velocity is the amount of mobility along one journey. Alternatively, velocity is a vector and speed is a scalar quantity.

The rate and direction of motion are measured by a vector known as velocity. The speed that something moves in one direction is known as its velocity. Velocity can be used to gauge both the speed of an oncoming car on a busy freeway and the speed of a rocket being launched into space.

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Only one genuine zero exists, and it is found at x = 1.359. newton's method to approximate the zero(s) of the function

The first three decimal places were repeated in the solution after the fourth iteration. I began by assuming that x = 1 was the answer to the Newton's Method formula.

When I entered 1 for x, I received a zero of 5/3.

I entered 5/3 and repeated the process to get 997/687.

I was able to get 1.36976 by plugging in 997/687 and repeating the process.

I entered 1.36976 and repeated the process to get 1.359454.

I entered 1.359454 and repeated the process to get 1.359304.

There was no need to go any further because we are only interested in accuracy to three decimal places.

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The required time need to fire the rockets to achieve the desired condition is by the relationship of centripetal acceleration by angular acceleration and angular velocity, t = [tex]\sqrt{gR}\frac{M}{2T}[/tex]

What is Centripetal Acceleration?

Centripetal acceleration is a characteristic of an object's motion along a circular path. Centripetal acceleration applies to any item travelling in a circle with an acceleration vector pointing in the direction of the circle's center. In your daily existence, you must have encountered numerous instances of centripetal acceleration. A centripetal acceleration occurs when you drive in a circle, and a centripetal acceleration also occurs when a satellite orbits the Earth. Centripetal refers to being in the middle.

Radius of the spaceship in the form of a wheel = R

Mass of the spaceship concentrated at its rim = M

Radial acceleration of any object placed on the spaceship = g

Thrust exerted by the rocket = T

Time needed to fire the rockets = t

I understand the question you are looking for

"A crew of scientists has built a new space station. The space station is shaped like a wheel of radius R with essentially all its mass M at the rim. When the crew arrives the station will be set rotating at a rate that causes an object at the rim to have radial acceleration g thereby simulating Earth's surface gravity. This is accomplished by two small rockets each with thrust T newtons mounted on the station's rim. How long a time t does one need to fire the rockets to achieve the desired condition?"

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The pipe at point b will have the least inner diameter based on the supplied statement.

Any liquid, gas, or substance in general that, while under stress, changes form continuously and is incapable of withstanding tangential or shearing forces.

Pipe size and water pressure are related in a moisture pipeline. Because if a pipe's diameter is reduced, the pressure inside the pipeline will rise. According to Bernoulli equation, pressure may be decreased by decreasing the area on conveyance. As a result, there is a high pressure at B and a low diameter at B.

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The complete question is-

An ideal fluid flows from left to right through this horizontal pipe, whose interior is hidden. A higher fluid level in the vertical pipes indicates a higher pressure inside the horizontal pipe. At which point does the pipe have the smallest inner diameter? (A higher fluid level in the vertical pipes indicates a higher pressure inside the horizontal pipe).

(A). Point a

(B). Point b

(C). Point c

(D). The diameter doesn't change

(E). We can't determine the diameter of the pipe.

If his near point is a typical 25cm, he must hold the gem that he is inspecting at 4.17cm in front of the magnifying lens that the jeweler is wearing.

It is a convex lens that is used to produce a magnified image of an object. The lens is usually mounted in a frame with a handle or wear it like an eyeglasses in front of our eye.

How to calculate, how close can he hold a gem that he is inspecting?
First, let's calculate the focal length of the lens.

f = 1 / P

= 1 / 20D

= 0.05m * ( 10^2 cm / 1m)

= 5cm

Convex lens will create a virtual image of a nearby object. Therefore, the image distance is taken as negative, di = -25cm

The position where the gem can be held is calculated with this formula :

1 / f = 1 / do + 1 / di

1 / do = 1 / f - 1 / di

= (1 / 5cm) - (1 / -25cm)

do = 4.17cm

Therefore, the jeweler needs to hold the gem at 4.17cm.  

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Answer:

T = 2 π (L / g)^1/2

T = 6.28 (5 m / 9.80 m/s^2)^1/2

T = 4.49 sec     (the period is not dependent on mass)

The Radius loop of 34.88m that coaster could go around with speed of 18.5m/s.

Mass of rollercoaster =2800kg

Speed is 18.5m/s

[tex]V=\sqrt{gR}\\ \\V=speed=18.5m/s\\\\g=gravity=9.81m/s^2\\\\R=radius[/tex]

Calculation- squaring both sides of equation.

[tex]V^2=gR\\\\R=V^2/g\\\\R=18.5^2/9.81\\\\R=342.25/9.81\\\\R=34.88m[/tex]

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The multiple of earth's radius which gives the radial distance is 4/3 or 1.33.

Initial speed = 0.745

However,

We know that escape velocity = V = √ (GM/2Rₓ)

So, using the property of energy conservation,

= (1/2)mv² - GMm/2Rₓ

= - GMm/r

The escape velocity, in astronomy and space exploration, is the velocity needed for a body to escape from a gravitational centre of attraction without undergoing any further acceleration. It is the minimum velocity required by a body to be projected to overcome the gravitational pull of the earth.

Thus,

= r = 4Rₓ / 3

Hence the multiple of Rₓ is 4/3 or 1.33.

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The small explosive charge produces only internal forces between the two stages of the rocket, so no external forces. Momentum is conserved.

=

( + )( ⁄) − ( )( ⁄)/

=

. / − . //

= . / /

=. / / = /s

Since this is positive the lower stage is moving in the same direction as the upper stage and both are in the same as the original direction.

Therefore, The small explosive charge produces only internal forces between the two stages of the rocket, so no external forces. Momentum is conserved.

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The addition of a fourth bulb will cause some of the three lights in a series circuit to become dim.

A wire filament is used in an electronic bulb, a compact and basic light source that emits light when power is applied. The illustration below shows the incandescent light bulb's construction. Three essential components make up the light bulb. the thread. glass lightbulb

An electrical device that generates light is known as an electric light, lamp, or lightbulb. The most prevalent type of artificial illumination is this. A lamp's base, which is often composed of ceramic, metal, glass, or plastic, attaches it in the socket of such a lighting system, which is also frequently referred to as a "lamp."

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a)The time constant of the circuit is  2sec.

b)The maximum charge on the capacitor is 0.18C

c)The charge on the capacitor at one time constant is 0.18×(1-(1/[tex]e^\frac{t}{500}[/tex]).

a)We have resistor resistance 100ohm,capacitor capacitance as 20mf and EMF value as 9V.

We know very well that the time constant of the circuit is defined as the product of Resistance and Capacitance, or in other words

τ=R×C

Therefore,τ=100ohm×20×10⁻³F

            =>τ=2sec.

b)The maximum charge on the capacitor is defined as the product of capacitance and voltage applied by the battery.

In other words, Q=C×E

                      =>Q=20×10⁻³F×9V

                       =>Q= 180×10⁻³C

                        =>Q=0.18C

c)Now,we need to find the charge on the capacitor at one constant time.We know very well that charge on the capacitor at any given time is represented by

q(t)=q₀(1−1 /[tex]e\frac{t}{RC}[/tex])

where q₀ is the maximum charge induced on the capacitor

Therefore, q(t)=0.18×(1-(1/[tex]e^\frac{t}{100.5}[/tex])

=>q(t)=0.18×(1-(1/[tex]e^\frac{t}{500}[/tex])

Hence, a)time constant is 2sec,b)maximum charge is 0.18C and c)charge at one time constant on capacitor is q(t)=0.18×(1-(1/[tex]e^\frac{t}{500}[/tex]).

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It is false to say that a ground wire is an essential component for a circuit breaker. So, given statement is false.

The reason for why it is off-base on the grounds is  that the seriousness of an electric shock relies upon how much flow streaming in it, not on the sort of material by which it is made. An electrical switch is an electrical wellbeing gadget intended to shield an electrical circuit from harm brought about by an overcurrent or cut off. Its essential capability is to hinder current stream to safeguard hardware and to forestall the gamble of fire.

Dissimilar to a wire, which works once and afterward should be supplanted, an electrical switch can be reset (either physically or naturally) to continue typical activity.

Circuit breakers are made in changing sizes, from little gadgets that safeguard low-current circuits or individual domestic devices, to huge switchgear intended to safeguard high voltage circuits taking care of a whole city. The conventional capability of an electrical switch, or circuit, as a programmed method for eliminating power from a broken framework, is frequently truncated as OCPD (Over Flow Insurance Gadget).

Hence, given statement is false.

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A specific example of a practical application of waves in medicine is the capturing of body structures to detect abnormalities in them.

Abnormality is the giant deviation from normally usual patterns of conduct, emotion, or notion, same time as normality is the absence of illness and the presence of a country of nicely being otherwise referred to as normalcy. It may be hard to attract the line between regular and strange behaviors, specifically in management.

Abnormality consists of 3 extraordinary classes; they're subnormal, supernormal, and paranormal. The technology of unusual psychology studies two types of behaviors: adaptive and maladaptive behaviors.

Apart from genes, similarly, organic elements that contribute effectively to the abnormality of 1's behavior are neurotransmitters and hormones. Imbalance in neurotransmitters like GABA, norepinephrine, and many others., causes unusual neural plasticity or mental dysfunction.

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The angular separation is 77.8°.

What is angular separation?

It is the angle between two point objects or sightlines, as seen from an observer. It is denoted by θ.

What is bragg's law?

Bragg's law states that "The reflected x-ray beam has the same angle of scattering as the incident beam when an x-ray beam strikes a crystal at an angle. When the path difference (d) is equal to the wavelength's whole number (n), constructive interference will result."

nλ = 2d sin θ

Separation of 532 lines = 1 mm, so the slit separation is,

d= 1 / 532 mm

=[tex](1.8 * 10^-^3mm) (\frac{10^-^3m}{1 mm)}[/tex] = [tex]1.8 * 10^-^6[/tex] m

The Bragg's equation is,

d sinθ = nλ

Rewrite the Bragg's equation for θ

θ = [tex]sin^-^1[/tex] [mλ / d ]

Thus, the angle of diffraction is,

θ = [tex]sin^-^1 [\frac{2(565 * 10^-^9) }{1.8 * 10^-^6}][/tex]

= 38.89°

Angular separation = 2θ

=2(38.89)°

= 77.78°

≅ 77.8°

The angular separation is 77.8°.

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B- 70 percent of the original strength for intermediate fabric.

What is  Fabric covering?

Fabrics are adaptable and employed in a wide range of industries, including clothing, agriculture, the military, and obviously the healthcare sector. More than you would imagine, specialty textiles are a part of our daily life. These textiles are generally flame resistant, mould and mildew resistant, and particularly treated with antibacterial properties for the healthcare sector. Why, I presume you ask? Because textiles used often in the medical field need to be antimicrobial and stain resistant from the start, this will help prevent bacteria from growing on the fabric surface.

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The magnitude of the magnetic field at the center of the loop 6.28  × 10⁻⁵ T.

A magnetic field is a vector subject that describes the magnetic effect on moving electric charges, electric currents, and magnetic materials. A transferring price in a magnetic area stories a pressure perpendicular to its very own pace and to the magnetic discipline.

calculation:-

Given;

Number of turns n  = 17 turns

radius = 11 cm = 0.11m

current i = 0.58 A

Magnetic field at the centre of the loop is

B = μ₀nI//2r

B = 4π × 10⁻⁷ × 17 × 0.58 / 2× 0.11

  = 628.4 × 10⁻⁷ T

   = 6.28  × 10⁻⁵ T

A magnetic field is a vector field that describes the magnetic influence on moving electric charges, electric-powered currents, and magnetic substances. A transferring rate in a magnetic field story a pressure perpendicular to its own velocity and to the magnetic area.

The magnetic field is the place around a magnet wherein the impact of magnetism is felt. We use the magnetic discipline as a tool to explain how the magnetic force is shipped in the area around and inside something magnetic in nature.

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No state of matter is required for energy transfer to occur when radiant energy is the source.

When radiant energy is the source,  it means we are talking about energy transfer by radiation, so matter is not needed for the energy to be transferred.

An example of this is the Sun as it heats up the Earth by radiation, even through the vacuum of outer space, where there is almost no matter.

Radiant energy is used for radiant heating that can be generated electrically by infrared lamps, or can be absorbed from sunlight and is used to heat water.

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Neptune and Uranus are similar in terms of size, mass, composition, and internal structure. The largest moon of Neptune, Triton, appears to have been captured because of its retrograde orbit.

Triton has a thin atmosphere and could be experiencing geological activity. Neptune's location was anticipated before it was ever discovered. Neptune is one of just two ice giants in the outer solar system (the other is Uranus). The planet's bulk, which is composed of a hot, dense fluid floating atop a tiny, rocky core, is primarily made up of water, methane, and ammonia (80% or more). Uranus is Neptune's identical twin. Their mass and chemical contents are equivalent. They are composed of an exterior layer of rocks and a mantle that is a mixture of water, ammonia, and methane ices.

Therefore, a physical body's mass is its total amount of matter. Inertia, or the body's resistance to acceleration (change of velocity) when a net force is applied, is also measured by this property. The gravitational pull an object has on other bodies is also influenced by its mass. The kilograms is the fundamental mass unit of SI (kg).

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In the first second, a slate drops from the roof of a tall building.

Second is the standard unit of time in the International System of Units (SI) (s or sec). In decimal form, one cycle of radiation, or 9,192,631,770 (9.192631770 x 109), is equal to one second. This radiation is produced as the cesium-133 atom moves between two levels.

The symbol for a second, or s, is used to denote SI time. It is described as the fixed numerical value of the cesium frequency, vCs, which is the unaltered ground-state hyperfine transition frequency of the cesium 133 atom. The unit Hz, which is equivalent to s-1, is used to express this frequency. The second is the unit of time measurement.

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The lost mass or mass defect that results in the mass of four protons being slightly greater than the mass of a helium nucleus is due to the conversion of matter to energy.

The lost mass or the mass defect is the difference in mass that is observed when the mass atoms of elements are compared to the sum of the mass of the constituents of all the particles in the nucleus of the atom.

For example, the mass of four protons is slightly greater than the mass of a helium nucleus that is also composed of four protons.

This loss in mass is known as the mass defect.

The loss in mass or mass defect is a result of the conversion of some of the mass of the particles to energy.

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