Question 1
4
An object is located 90 m in front of a lens. An image is produced 40 m away from the
lens. What is the focal length of the lens?
O 15.3 m
0.025 m
O 27.7 m
O .011 m

Answers

Answer 1
1/f= 1/di+1/do
1/f=1/90m+1/40m
1/f ≈27.7m

Related Questions

An electromagnet is a device that uses an electric current to produce a magnetic field.

Electromagnets are typically composed of a piece of metal wrapped with wire and connected to a battery. The battery provides the electric current, and the loops or coils of wire enhance the magnetic field. The more loops there are, the stronger the magnetic field.

When electric current flows through the electromagnet, the metal core becomes magnetized, so it possesses a north pole and a south pole.

Motors place electromagnets inside of permanent magnets as shown below.



However, motors are designed so that the polarity of the electromagnet constantly flips. That is, the north pole becomes the south pole, and the south pole becomes the north pole, every time the electromagnet turns 180 degrees.

Why is it designed this way?
A.
to conserve the energy in the battery
B.
to constantly polarize the field magnet
C.
so the electromagnet will continuously turn
D.
so the magnetic field will get stronger

Answers

The reason why motors are designed so that the polarity of the electromagnet constantly flips.is

C. so the electromagnet will continuously turn

Why is motor designed that way

The reason motors are designed so that the polarity of the electromagnet constantly flips is to continuously turn the electromagnet. This allows the motor to rotate continuously, rather than becoming stuck in one position.

The flipping of the polarity causes the electromagnet to attract and repel from the permanent magnets, creating a rotating motion.

Therefore, the correct answer is C.

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Define and describe the following terms: amplitude, wavelength, frequency, period, tension.

Answers

Answer:

Amplitude—distance between the resting position and the maximum displacement of the wave

Frequency—number of waves passing by a specific point per second

Period—time it takes for one wave cycle to complete

wavelength λ - the distance between adjacent identical parts of a wave, parallel to the direction of propagation.

Tension - described as the pulling force transmitted axially by the means of a string, a cable, chain, or similar one-dimensional continuous object, or by each end of a rod, truss member, or similar three-dimensional object

How does the motion of the molecules change when you increase the temperature

Answers

Answer:

They speed up as temperature increases.

Explanation:

As temperatures increases within a molecule the particles will speed up.

Una carga de 4 nC es transportada desde el suelo hasta la superficie de una esfera cargada con un trabajo de 7 X 10-5 j. Determinar el potencial eléctrico de la esfera

Answers

Respuesta:

2 × 10⁴ V

Explicación:

Paso 1: Información provista

Carga transportada (q): 4 nCTrabajo realizado (W): 7 × 10⁻⁵ J

Paso 2: Convertir q a Coulomb

Usaremos el factor de conversión 1 C = 10⁹ nC.

4 nC × 1 C/10⁹ nC = 4 × 10⁻⁹ C

Paso 3: Calcular el potencial eléctrico (V) de la esfera

Usaremos la siguiente fórmula.

V = W/q

V = 7 × 10⁻⁵ J/4 × 10⁻⁹ C = 2 × 10⁴ V

Why does the golf ball sink in
water, while the beach ball
floats?

A- The beach ball weighs less than
the golf ball
B- The golf ball has a higher density
than the beach ball
C- The beach ball has a higher
density than the golf ball
D- The golf ball has more mass than
the beach ball

Answers

B is the correct answer.
The right answer is B

2. Give at least 2 major roles of mining in our lives.

Answers

Answer:

Mined materials are needed to construct roads and hospitals, to build automobiles and houses, to make computers and satellites, to generate electricity, and to provide the many other goods and services that consumers enjoy.

Explanation:

The force of gravity between you and Earth is greater than the force of gravity between you and a car because Earth has more __________ than the car.​

Answers

The answer for this question is mass

Answer:Earth has more mass than the car.

in the question

The average mass of an adult American female is 75 kilograms. What is the weight of
the average female in pounds?

Answers

Answer:

with 75kg --> 165.35 pound(lb)

Explanation:

[tex] \frac{75}{0.45359237} [/tex]

The average weight is 165 pounds since 1 kilo is 2.2 lbs. 2.2*75=165

A stereo speaker is made of a flexible cone-shaped material that vibrates, creating a sound wave. A sound wave formed be a speaker travels through air to your ear as a series of compressions and rarefactions of air molecules.

Which statement classifies the sound wave?

transverse wave in which the particles of the wave move in a direction parallel to the wave motion

longitudinal wave in which the particles of the wave move in a direction parallel to the wave motion

transverse wave in which the particles of the wave move in a direction perpendicular to the wave motion

O longitudinal wave in which the particles of the wave move in a direction perpendicular to the wave motion

Answers

Answer: longitudinal wave in which the particles of the wave move in a direction parallel to the wave motion

The sound wave is a longitudinal wave in which the particles of the wave move in a direction parallel to the wave motion.

What is a wave of sound?

A sound wave can be described as the pattern of distribution caused by the movement of energy that is traveling through a medium, such as air, water, or any liquid or solid matter, etc, as it is traveling away from the source of the sound. There are two types of sound waves:

Longitudinal wave: When the particles of the medium move in a direction parallel to the direction that the wave moves then the wave is known as the longitudinal wave.

Transverse Wave: When the particles of the medium move in a direction perpendicular to the direction that the wave moves then the wave are known as the transverse wave.

As it is given that the sound wave formed by the speaker travels through the air to your ear as a series of compressions and rarefactions of air molecules, therefore, the particles of the medium move in a direction parallel to the direction that the wave.

Hence, the sound wave is a longitudinal wave in which the particles of the wave move in a direction parallel to the wave motion.

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What is the acceleration of a 250 kg object pushed with a force of 7500 newtons?

Answers

Answer:

a = 30 m/s²

Explanation:

Given: 250 kg, 7500N    

To find: Acceleration (a)    

Solution: To find the acceleration (A), divide the force by the weight  

A = F ÷ m

=  7500 ÷  250

= 30 m/s²

Newtons are derived units, equal to 1 kg-m/s². In other words, a single Newton is equal to the force needed to accelerate one kilogram one meter per second squared.

Use Newton's second law of motion and a free-body diagram to...
1. ...calculate the normal force acting upon a 50-kg passenger who accelerates upward at a rate of 3.0 m/s/s.
2. ...calculate the normal force acting upon a 50-kg passenger who accelerates downward at a rate of 3.0 m/s/s.
Please don't put any links or I will report you.

Answers

Using the formula F = m*a. where F is the force, m is the mass and a is the acceleration you can use it for each. As long as there are no other forces towards the body in both cases :
F = m*a
F = 50*3
F = 150 N

What formula should I use?

Answers

these nuts on your chin

A 74.2 kg teenager slides down a frictionless slide that has an angle of inclination of 38˚. What is the magnitude of the acceleration of the teenager down the slide?

Answers

Answer:

Explanation:

This is one-dimensional motion on an incline which makes it so much more funner :/

The equation for this is

w*sinθ - f = ma which is just a fancy version of Newton's second law that says that the sum of the forces acting on an object are equal to that object's mass times its acceleration.

w is the weight of the teen which is also the normal force, [tex]F_n[/tex]. Therefore,

[tex]w=F_n=mg[/tex] where m is mass and g is gravity:

[tex]w=F_n=(74.2)(9.8)[/tex] and we need 2 sig figs for this since there are 2 in 9.8:

w = 730N

Since there is no friction in this problem, the value for f, frictional force, is 0, making our job a bit shorter. Filling in the main equation:

730sin38 - 0 = 74.2a

Since the left side is subtraction and we will eventually have to divide, and the rules for subtraction/addition are different from those for multiplication/division, we will have to subtract first, get the correct number of sig figs for that difference, and then divide, following the rules for division.

730sin38 will have 2 sig figs which is 450. Now

450 - 0 = 74.2a and

450 = 74.2a and divide to 2 sig figs:

a = 6.1 m/s/s

If a body is thrown up with an initial velocity 'u' and covers a maximum height of 'h' , then 'h' is equal to u²/2g
Explain in detail.​

Answers

Answer:

1/2 m u^2     initial Kinetic Energy of body

m g h        Potential Energy body attains as it rises to height

1/2 m u^2 = m g h      conversion of KE to PE

h = u^2 / ( 2  g)

Which beach balls have potential energy and not kinetic energy?

Answers

Answer:

Beach ball 4

Explanation:

it is because, Potential Energy = M G H

P(e) directly proportional to H.

if H increase then P energy also increases

How is it possible a plant can sustain itself for 70 years locked inside a jar ?

Answers

Answer:

If you are talking about the experiment in which mouse and plants are kept in a closed glass jar in sunlight so in that case, they both survive because the CO2 released by the respiration of mouse is being utilized by the plants and fixed ( phosynthesis) and O2 is released as by product, which is taken by the mouse for respiration.

Our entire ______ _____
is built in the backbone of metals.

Answers

Answer:

modern world

Explanation:

1.-Una fuerza horizontal de 40 N es apenas suficiente para poner en marcha un trineo de 600 N sobre nieve compacta. Después de empezar el movimiento se requieren tan solo 10 N para mantener el trineo a rapidez constante. Halle los coeficientes de fricción estática y cinética

Answers

Answer:

Los coeficientes de fricción estática y cinética son [tex]\frac{1}{15}[/tex] y [tex]\frac{1}{60}[/tex], respectivamente.

Explanation:

Por la Primera Ley de Newton, sabemos que la fuerza externa debe tener igual magnitud y dirección contraria a la fuerza de reacción (fricción). Puesto que el trineo se mueve sobre una superficie horizontal, la magnitud de la fuerza normal es la del peso ([tex]W[/tex]), en newtons. El coeficiente de fricción estática ([tex]\mu_{s}[/tex]), sin unidad, es la razón de la fuerza de fricción justo antes del movimiento inminente ([tex]F[/tex]), en newtons, a la fuerza normal ([tex]N[/tex]), en newtons:

[tex]\mu_{s} = \frac{F}{W}[/tex] (1)

Si sabemos que [tex]F = 40\,N[/tex] y [tex]W = 600\,N[/tex], entonces el coeficiente de fricción estática es:

[tex]\mu_{s} = \frac{F}{W}[/tex]

[tex]\mu_{s} = \frac{40\,N}{600\,N}[/tex]

[tex]\mu_{s} = \frac{1}{15}[/tex]

El coeficiente de fricción cinética ([tex]\mu_{k}[/tex]), sin unidad, es la razón de la fuerza de fricción experimentada por el trineo en movimiento ([tex]F[/tex]), en newtons, a la fuerza normal:

[tex]\mu_{k} = \frac{F}{W}[/tex] (2)

Si sabemos que [tex]F = 10\,N[/tex] y [tex]W = 600\,N[/tex], entonces el coeficiente de fricción cinética es:

[tex]\mu_{k} = \frac{F}{W}[/tex]

[tex]\mu_{k} = \frac{10\,N}{600\,N}[/tex]

[tex]\mu_{k} = \frac{1}{60}[/tex]

Los coeficientes de fricción estática y cinética son [tex]\frac{1}{15}[/tex] y [tex]\frac{1}{60}[/tex], respectivamente.

The three things to remember about gravitational forces in space are: 1. 2. 3.

Answers

Answer:

(1) The gravitational forces are inversely proportional to the square of the distance between the objects. More is the distance between the objects , less will be the gravitational force between them.

(2) The gravitational forces are the weakest of all the four fundamental forces (Nuclear forces, weak forces, electromagnetic forces, gravitational forces) in nature.

(3)Gravitational forces are always attractive . They are also conservative in nature. work done by these forces or against these forces doesn't depend on the path followed.

Explanation:

John often sees squiggly lines when he looks at a bright sky or white paper. His doctor says that they are called eye floaters, which are small bits of protein in the fluid that fills the eyeball.
In what part of the eye are eye floaters found?
a) cornea
b) vitreous humor
c) retina
d) convex lens

Answers

Answer- It's B, i double checked it on a few websites

The vitreous humor is the eye is eye floaters.

What is vitreous humor?

The vitreous body (vitreous meaning "glass-like"; from Latin vitreus 'glassy', from vitrum 'glass', and -eus) is the clear gel that fills the space between the lens and the retina of the eyeball (the vitreous chamber) in humans and other vertebrates. It is often referred to as the vitreous humor (also spelled humour, from Latin meaning liquid) or simply "the vitreous". Vitreous fluid or "liquid vitreous" is the liquid component of the vitreous gel, found after a vitreous detachment. It is not to be confused with the aqueous humor, the other fluid in the eye that is found between the cornea and lens.

Structure

The vitreous humor is a transparent, colorless, gelatinous mass that fills the space in the eye between the lens and the retina. It is surrounded by a layer of collagen called the vitreous membrane (or hyaloid membrane or vitreous cortex) separating it from the rest of the eye. It makes up four-fifths of the volume of the eyeball.The vitreous humour is fluid-like near the centre, and gel-like near the edges.

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who is the first physicist and what did he invented?​

Answers

Answer:

hippocrates

I guess..........

What is a pulley and the how does it make lifting heavy loads easier?

Answers

It uses kinetic energy

A specified volume of space contains an electric field for which the magnitude is given by E=E0cos(ωt). Suppose that E0 = 20 V/m and ω = 1.0 × 107 s−1. What is the maximum displacement current through a 0.40 m2 cross-sectional area of this volume?

Answers

Answer: [tex]0.708\ mA[/tex]

Explanation:

Given

[tex]E_o=20\ V/m[/tex]

[tex]\omega =10^7\ s^{-1}[/tex]

Cross-sectional area [tex]A=0.40\ m^2[/tex]

Current density is given by

[tex]J=\epsilon_o \dfrac{dE}{dt}[/tex]

Displacement current

[tex]\Rightarrow I=JA\\\Rightarrow I=8.854\times 10^{-12}\times 20\times 10^7\times 0.4\\\Rightarrow I=0.708\times 10^{-3}\ A[/tex]

The required value of the maximum displacement current of the given space is  [tex]7.08 \times 10^{-4} \;\rm A[/tex].

Given data:

The intensity of electric field is, [tex]E_{0}=20 \;\rm V/m[/tex].

The angular frequency of electric field is, [tex]\omega=1.0 \times 10^{7} \;\rm s^{-1}[/tex].

The cross-sectional area of space is, [tex]A =0.40 \;\rm m^{2}[/tex].

In the given problem, the instantaneous electric field is given by [tex]E = E_{0} \times cos(\omega t)[/tex]

So, the expression for the current density is,

[tex]J= \epsilon_{0} \times \dfrac{dE}{dt}[/tex]

Here, [tex]\epsilon_{0}[/tex]  is the permittivity of free space. Solving as,

[tex]J= \epsilon_{0} \times \dfrac{d(E_{0} \times cos(\omega t))}{dt}\\\\J= -\epsilon_{0} \times E_{0} \times \omega \times sin(\omega t)[/tex]

And the expression for the maximum displacement current is,

[tex]I = J \times A[/tex]

And the maximum displacement current is possible only when, J is positive and J will be positive for  [tex]sin(\omega t)=-1[/tex].

Then solving as,

[tex]I = (-\epsilon_{0} \times E_{0} \times \omega \times sin(\omega t)) \times A\\\\I = (-8.85 \times 10^{-12} \times 20 \times (1.0 \times 10^{7}) \times (-1)) \times 0.40\\\\I = 7.08 \times 10^{-4} \;\rm A[/tex]

Thus, we can conclude that the required value of the maximum displacement current of the given space is  [tex]7.08 \times 10^{-4} \;\rm A[/tex].

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Which of these statements explains why we have day and night? [1] The Earth orbits the Sun once a day The Sun orbits the Earth once a day. The Sun spins on its axis once a day. The Earth spins on its axis once a day.

Answers

Answer:

The Earth spins on its axis once a day.

Explanation:

In simple words,The Earth revolves on its axis once every 24 hours and circles the sun once every 365 days. The Earth's rotation on its axis, not its orbit throughout the sun causes day as well as night. The word 'one day' refers to the period it requires the Earth to spin entirely on its axis, which involves both day as well as night.

help.....please science​

Answers

Answer:

please mark me brainliest

Explanation:

ohm

The SI-derived unit of electric resistance is the ohm, which is defined as a volt per ampere.

Answer:

I cant see that

what is the mineral salt
intake of chlorophytes​

Answers

Explanation:

Microalgae can offer several benefits for wastewater treatment with their ability to produce large amounts of lipids for biofuel production and the high economic value of harvested biomass for biogas and fertilizer. This study found that salt concentration (∼ 45 g L⁻¹) had more of an effect than salt type on metabolisms of Chlorella vulgaris for wastewater treatment and biofuel production. Salinity stress decreased the algal growth rate in wastewater by 0.003 day⁻¹ per mS cm⁻¹ and slightly reduced nutrient removal rates. However, salinity stress was shown to increase total lipid content from 11.5% to 16.1% while also increasing the saturated portions of fatty acids in C. vulgaris. In addition, salinity increased the algal settling rate from 0.06 to 0.11 m day⁻¹ which could potentially reduce the cost of harvesting for algal biofuel production. Overall, C. vulgaris makes a suitable candidate for high salinity wastewater cultivation and biofuel production.

Answer:

High bioavailability- chloride, fluoride, iodine, potassium, sodium

Low bioavailability- Chromium, iron, manganese, zinc

Explanation:

Essential Minerals there are 16 of them.

Hope this helps you :)

A step down transformer has a primary coil consisting of 700 tons and a secondary coil consisting of 300 times. What is the potential difference in the second circuit, if the primary coil is supplied with an effective AC potential difference of 110 V?

Answers

Answer is 47.14 v

by the relation

[tex]\frac{V out}{V in } = \frac{N secondary}{N primary }[/tex]

If you're the white mouse, what will you do in order for you to survive​

Answers

Answer:

If I was the white mouse, I would either find somewhere to hide that matches my fur color to camoflouge with or dig into the dirt so less visible.

To find white colour habitat.

What will I do for my survival?

If I was the white mouse, I would find white colour place for living because in that white colour the predators can't see me and i will be safe from them so we can conclude that finding white colour habitat is the best choice to safe myself.

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As you change the amplitude, does the wavelength change?

Answers

Answer:

Explanation:

Amplitude does not affect wavelength. It also does not affect wave speed. Amplitude is the energy of the wave measured from the rest position to the top of the crest.

Hope this Helped!!!

Answer:

False

Explanation:

Amplitude does not affect wavelength. It also does not affect wave speed.

Amplitude is the energy of the wave measured from the rest position to the top of the crest. A wave with more energy has a higher up crest/ higher amplitude.

In 1993, the gold reserves in the United States were about 8.490 × 106
kg. If all
that gold were made into a thick wire with a cross-sectional area of 1cm2
, its
total resistance would be about 6.60 × 102 Ω. If the same operation were
applied to the gold reserves of Germany, France, and Switzerland, the
resistances would be 2.40 × 102 Ω, 2.00 × 102 Ω, and 2.00 × 102 Ω,
respectively. Now consider all four resistors connected as shown in the circuit
diagram below. Find the equivalent resistance.

Answers

The equivalent resistance of the circuit is 65.98 Ω.

What is Resistor?

A resistor is an electrical component that limits or regulates the flow of electrical current in a circuit. It is designed to provide a specific amount of resistance to the flow of electrons, measured in ohms, and is typically made of a material that can resist the flow of electricity, such as carbon or metal. Resistors are used in a wide range of electronic devices and circuits, from simple LED flashers to complex computer systems.

To find the equivalent resistance of the circuit, we need to use the formula for resistors in parallel:

1/Req = 1/R1 + 1/R2 + 1/R3 + 1/R4

where Req is the equivalent resistance, and R1, R2, R3, and R4 are the resistances of the four resistors.

Substituting the given values, we get:

1/Req = 1/6.60 × 102 + 1/2.40 × 102 + 1/2.00 × 102 + 1/2.00 × 102

1/Req = 0.01515

Req = 65.98 Ω

Therefore, the equivalent resistance of the circuit is 65.98 Ω.

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Choose the "S" image used in the D.S. al Fine. Beth wants to buy a radio for $36. Shegives the cashier $40. What is herchange? Which statement is incorrect about the adult human heart?Question 28 options:Blood in the right ventricle is deoxygenated.Blood in the left ventricle is deoxygenated.Blood in the pulmonary artery is deoxygenated.Blood in the pulmonary vein is oxygenated.Answer not listed Which word in this sentence should begin with a capital letter?The book frankenstein was a good read.A. frankensteinB. bookC. readD. readE. was In 1941, Hitler sent in the German tank force, the Afrika Korps, in response to what? Italys heavy losses to the US in North Africa Germanys heavy losses to the British in North Africa Britains heavy losses to the Italians in North Africa Italys heavy losses to the British in North Africa dominic is buying candy by the pound for a party. for every 10 pounds of candy he buys, he pay $12. What is the cost of the candy, per pound, for the candy? If you multiply 2 xr you will get the ....? 6th grade advanced / 7th grade 5 x (-2w - 4) = (__) In which group of indigenous people are the Tanos believed to have belonged? A. the hunter-gatherers who did not farm B. the farmers and ceramic makers C. the farmers and ceramic makers with social structures and religion D. the disease-stricken group of colonial times What Kind of Mutation is demonstrated? ON THE TOP : FOAM :: ON THE BOTTOM : How do you think a peace treaty can cause war instead of creating peace? if there is a bottle of grape juice with 20% juice and there is 1000mL of total drink, how many mL of wateris in the bottle? Lilian drove into a lorry park at 11 55 When she drove out of the lorry park she had to pay 9 euros Which of the following points are solutions to the equation 3x - 4y - 8 = 12?Select all that apply.(0-5)(82)(-16-17)(-1,-8)(-40,-34) If y varies inversely as x, and y= 4 when x=6, then determine the value of y when x=5. Net Zero Products, a wholesaler of sustainable raw materials, prepares the following aging of receivables analysis. Days Past Due Total 0 1 to 30 31 to 60 61 to 90 Over 90 Accounts receivable $ 185,000 $ 100,000 $ 38,000 $ 17,000 $ 14,000 $ 16,000 Percent uncollectible 1 % 2 % 4 % 6 % 10 % 1. Estimate the balance of the Allowance for Doubtful Accounts using the aging of accounts receivable method. 2. Prepare the adjusting entry to record bad debts expense assuming the unadjusted balance in the Allowance for Doubtful Accounts is a $3,000 credit. what was the name of the new nation formed by southern states upon their withdrawel from the union You decide to take your car on a drive through Canada, where gas is sold in liters and distances are measured in kilometers. Suppose your car's gas efficiency is 23.0 mi/gal. How many liters of gas will you need to complete a 495 km trip? Use the conversions 1 gal = 3.78 L and 1 km = 0.6214 mi. What inference can you make by contrasting the ideas in the first two stanzas of the poem to the last stanza?A) The speaker is fascinated by the tempest, but glad to see it leave. B) The awful tempest is fearful at first, then saddened by the morning sun. C) The awful tempest is saddened at first, then fearful of the morning sun. D) The awful tempest rages all night long and terrifies the speaker of the poem.