Why might a scientist use a physical model of a plant cell instead of studying
a cell directly?
A. A model can be used for things that are too hot to handle easily.
B. A model can be used for things that are too small to see clearly.
C. A model can be used for things that are too large to study directly.
D. A model can be used for things that are too simple to study
directly

Answers

Answer 1

B. A model can be used for things that are too small to see clearly


Related Questions

The weight of an object is the force pulling the object:

a. upward
b. to the side.
c. in all directions
d. downward

Answers

D pulling because of gravity

Set three resistances to 2, 3, and 5 Ohms in series, and determine the current in the circuit with an ammeter. Take the snapshot of the screen showing the circuits and the reading of the ammeter. Then, replace these three resistors with just one resistance of 10 Ohm. Determine the current running in the circuit. Take a snapshot showing the circuits and the reading of the ammeter. Is the current the same as in the previous experiment with the three resistors

Answers

Answer:

the current in the circuit must be the same.

Explanation:

The equivalent resistance in a series circuit is the sum of the resistances

in this case

          R_{eq} = R₁ + R₂ + R₃

we calculate

          R_{eq} = 2 + 3 + 5

          R_{eq} = 10 Ω

We can see that the equivalent resistance is equal to the resistance to be changed, so the current in the circuit must be the same.

The only change there may be is due to the tolerances of the resistors

A container in the shape of a cube 11.6 cm on each edge contains air (with equivalent molar mass 28.9 g/mol) at atmospheric pressure and temperature 291 K. (a) Find the mass of the gas. kg (b) Find the gravitational force exerted on it. mN (c) Find the force it exerts on each face of the cube. kN (d) Why does such a small sample exert such a great force

Answers

Answer:

a.  0.00189 kg

b. 18.552 mN

c. 1.363 kN

d. Since the molecular density is high, the force exerted by the sample is thus high.

Explanation:

(a) Find the mass of the gas. kg

Using PV = mRT/M where P = pressure on gas = atmospheric pressure = 1.013 × 10⁵ Pa, V = volume of gas = L³ where L = length of cube = 11.6 cm = 0.116 cm,m = mas of gas, R = molar gas constant = 8.314 J/mol-K, T = temperature of gas = 291 K and M = molar mass of gas = 28.9 g/mol

So, m = PVM/RT = PL³M/RT

Substituting the values of the variables into the equation, we have

m = PL³M/RT

= 1.013 × 10⁵ Pa × (0.116)³ × 28.9 g/mol/ 8.314 J/mol-K × 291 K

= 0.0457 × 10⁵ Pa g/mol/2419.374J/mol

= 1.89 × 10⁻⁵ × 10⁵ g

= 1.89 g

= 1.89 × 10⁻³kg

= 0.00189 kg

(b) Find the gravitational force exerted on it. mN

The gravitational force, F exerted on it is its weight W

So, F = W = mg where m = mass of gas = 1.89 × 10⁻³ kg and g = acceleration due to gravity = 9.8 m/s²

F = mg

= 1.89 × 10⁻³ kg × 9.8 m/s²

= 18.522 × 10⁻³ kgm/s²

= 18.552 × 10⁻³ N

= 18.552 mN

(c) Find the force it exerts on each face of the cube. kN

Since pressure, P = F/A where F = force exerted on each face and A = area of each face = L² where L = length of side of cube = 11.6 cm = 0.116 m

So, F = PA since P = atmospheric pressure = 1.013 × 10⁵ Pa,

F = PL²

= 1.013 × 10⁵ Pa (0.116 m)²

= 0.01363 × 10⁵ N

= 1.363 × 10³ N

= 1.363 kN

(d) Why does such a small sample exert such a great force

To answer this question, we need to find the density of the gas in the cube.

So density of gas,ρ = m/V where m = mass of gas = 1.89 g and V = volume of gas = L³ and L = length of side of cube = 11.6 cm

ρ = m/V = m/L³ = 1.89 g/(11.6 cm)³ = 1.89 g/1560.896 cm³ = 0.00121 g/cm³

We now find the number of moles of gas in a cm³ by dividing its density by its molar mass.

So n = ρ/M = 0.00121 g/cm³ ÷ 28.9 g/mol = 23687.67 mol/cm³

Since there are 6.022 × 10²³/mol, we find the number of molecules in a cm³ which is n × 6.022 × 10²³/mol = 23687.67 mol/cm³ × 6.022 × 10²³/mol

= 143731.1 × 10²³ molecules/cm³

= 1.437311 × 10²⁸ molecules/cm³

≅ 1.44 × 10²⁸ molecules/cm³

Since the molecular density is high, the force exerted by the sample is thus high.

Newton's first law of motion states that an object's motion will not change unless

Answers

Answer:

unless an external unbalanced force acts on it.

Answer:

An object in motion will not change unless an external force acted upon it.

If I have an object with a 6.0 µC charge , and another with a -2.0 µC charge, when they touch how do I find the new charges

Answers

When charged objects touch, you can assume that the charges move between the objects, so that the total amount of charge doesn't change but it splits equally between the two objects.

-- like two water tanks standing next to each other, with a different amount of water in each one.  When you connect a pipe between their bottoms, some water flows across until the LEVEL of water is the same in both tanks.

-- like one hard full balloon and one soft mooshy balloon.  When you connect them together, some air flows from the hard balloon into the soft balloon, until the pressure of air is the same in both balloons.  

The total amount of charge on your two objects is (+6.0 μC  -  2.0 μC).  That's +4.0 μC  .

When they touch, charges move around until the charge is the same on both objects . . . +2 μC.

A 45.7 kg woman starts from rest at the bottom of a flight of stairs that has
a total height of 2.54 meters. She reaches the top of the stairs
in 5.00 seconds. How much power does she generate if she is moving at
2.63 m/s at the top of the stairs? Use g = 9.8 m/s2, and only include 3
numbers in your answer.

Answers

Answer:

The power generated by the woman is 259 W

Explanation:

Given;

mass of the woman, m = 45.7 kg

initial velocity of the woman, u = 0

total height ascended by the woman, h = 2.54 m

time of the woman's motion, t = 5.0 s

final velocity of the woman, v = 2.63 m/s

acceleration due to gravity, g =  9.8 m/s²

The potential energy of the woman due to the height she ascended;

P.E = mgh

P.E = 45.7 x 9.8 x 2.54

P.E = 1137.564 J

The kinetic energy of the woman due to her final velocity;

K.E = ¹/₂mv²

K.E = ¹/₂ x 45.7 x (2.63)²

K.E = 158.051 J

The total mechanical energy of the woman at the top of the stairs;

M.E = P.E + K.E

M.E = 1137.564 J  +  158.051 J

M.E = 1295.615 J

The power generated by the woman;

Power = Energy/time

Power = 1295.615 J / 5 s

Power = 259.123 W

Power = 259 W

How are newtons third law and his law of universal gravitation are connected

Answers

Answer:

please give me brainlist and follow

Explanation:

Gravitational force keeps it attracted to the Earth, and centripetal force keeps it moving in a circle. ... Explain how Newton's third law and his law of universal gravitation are connected. His third law states that every force has an equal opposite force attracted to it, and that force is caused by gravity.

What is The substance that dissolves the solute.

Answers

Answer:

Explanation:

Do you mean the solvent? If this is off the mark, let me know in a comment.

The solvent is something that the solute is (usually) soluble in.

Atoms of the gas neon

Answers

Explanation:

Neon is an atom with atomic number ten. Its atomic weight is 20.179 which cause it to have ten neutrons and ten protons in its nucleus and ten electrons outside. Neon; Neon, Ne, is a colorless inert noble gas and it is also the second lightest noble gas.

HELP PLEASEEEEEEEEEEE

Answers

Answer:

dolphin and wolf

Explanation:

the sharks jaw is way to small for it and is shaped differently

Why do you think geologists were able to use these P and S seismic waves to confirm that the outer core is liquid?

Answers

Using waves of frequency and pich

Explanation:

There's always been water around us

if a fly gets his wings cut of, is it still a fly?

Answers

Answer:

Yes I think... But the joke is it is a walk then.

Answer:

no

Explanation:

because if the fly get its wings cut off its obviously not going to be able to fly

Fizik
Dua perintang 5 Ω dan 10 Ω disambung selari dengan 9 V bekalan kuasa. Kira kuasa output bekalan kuasa.​

Answers

Answer:

P = 24.32 W

Explanation:

The question is, "Two resistors 5 Ω and 10 Ω are connected in parallel with a 9 V power supply. Calculate the output power of the power supply.".

The voltage of the power supply, V = 9 V

Resistor 1, R₁ = 5 Ω

R₂ = 10 Ω

The equivalent of parallel combination of resistors is given by :

[tex]\dfrac{1}{R_{eq}}=\dfrac{1}{R_1}+\dfrac{1}{R_2}\\\\\dfrac{1}{R_{eq}}=\dfrac{1}{5}+\dfrac{1}{10}\\\\R_{eq}=3.33\ \Omega[/tex]

The power of the output is given by :

[tex]P=\dfrac{V^2}{R_{eq}}\\\\=\dfrac{9^2}{3.33}\\\\P=24.32\ W[/tex]

So, the output power is equal to 24.32 W.

: A small block with mass 0.130 kg is attached to a string passing through a hole in a frictionless, horizontal surface. The block is originally revolving in a circle with a radius of 0.800 m about the hole with a tangential speed of 4.00 m/s. The string is then pulled slowly from below, shortening the radius of the circle in which the block revolves. The breaking strength of the string is 30.0 N. What is the radius of the circle when the string breaks

Answers

Answer:

r = 0.0173 m = 1.73 cm

Explanation:

Here, the centripetal force of the block will be providing the required breaking tension in the string:

[tex]Tension = Centripetal Force\\T = F_c\\\\T = \frac{mv^2}{r} \\\\r = \frac{mv^2}{T}\\[/tex]

where,

r = radius = ?

m = mass of block = 0.13 kg

v = tangential spee of block = 4 m/s

T = Breaking Strength = 30 N

Therefore,

[tex]r = \frac{(0.13\ kg)(4\ m/s)^2}{30\ N}[/tex]

r = 0.0173 m = 1.73 cm

When finding the radius of the string at the point it breaks, the tangential

velocity is assumed to be constant.

The radius when the string breaks is [tex]\underline{6.9 . \overline 3 \times 10^{-3}} \ m[/tex]

Reasons:

The mass of the small block, m = 0.130 kg

Initial radius of the circle of rotation = 0.800 m

Tangential velocity, v = 4.00 m/s

The radius of the path of rotation is reduced as the string is pulled

Breaking strength of the string = 30.0 N

Required:

The radius of the circle when the string brakes

Solution:

[tex]Centripetal \ force = \dfrac{m \cdot v^2}{r}[/tex]

Where;

r = The radius of the circle of rotation

When the string brakes, w have;

Centripetal force = Breaking strength of the string = 30.0 N

Which gives;

[tex]\displaystyle r = \mathbf{\dfrac{m \cdot v^2}{Centrifugal \ force}} = \frac{0.130 \times 4^2}{30} =6.9\overline 3 \times 10^{-2}[/tex]

The radius of the circle when, the string breaks r = [tex]\underline{6.9\overline 3 \times 10^{-2}} \ m[/tex]

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Jane told jill that the name sunflower comes from the fact that sunflowers follow the sun in the sky through out the day. jane said that sunflowers actually turn around on their stems to find the sun. to test this idea, jane and jill designed an experiment. they grew a pot of sunflowers outside in natural sunlight, one pot in the house near, but not directly in front of a window, and the final pot inside the house, away from all windows. the girls charted the direction of the sunflower heads throughout the day. all other growing conditions were the same: soil, water, pot size. the girls could not regulate the outdoor temperature, but since it was spring, the day and night temperatures were pretty close to the indoor temperature. which is an appropriate hypothesis for this experiment?


a) sunflowers will only grow in natural light.


b) sunflowers grown indoors will bend toward a source of natural light.


c) sunflower heads turn to follow the location of the sun, both indoors and out.


d) sunflowers grown away from natural light will not be as tall as sunflowers grown outdoors.

Answers

c.) sunflower heads turn to follow the location of the sun both indoors and out

How does Newton’s first second and third laws apply to eating your breakfast

Answers

Answer:

Newton's third law states that for every action (force) in nature there is an equal and opposite reaction. In other words, if object A exerts a force on object B, then object B also exerts an equal and opposite force on object A. Notice that the forces are exerted on different objects. However much you push your fork in the food, that much a dent it will cause.

Explanation:

Answer:

¡I hope it helps you! :) .................

Suppose a proton ( = 1. 67×10^−27 kg) is confined to a box of width = 1. 00×10^−14 m (a typical nuclear radius).
1. What are the energies of the ground and the first excited states?
2. If the proton makes a transition from the first excited state to the ground state, what are the energy and the frequency of the emitted photon?

Answers

Answer:

22e837281949222324

Explanation:

A 4.0 kg mass has a velocity of 10 m/s to the EAST. The 4.0 kg mass is subjected to a constant net force of 16 N to the WEST for 3.0 sec. What is the velocity of the 4.0 kg mass at the end of the 3.0 sec interval?​

Answers

Answer:

Explanation:

A 4.0 kg mass has a velocity of 10 m/s to the EAST. The 4.0 kg mass is subjected to a constant net force of 16 N to the WEST for 3.0 sec. What is the velocity of the 4.0 kg mass at the end of the 3.0 sec interval?​

The final velocity of the 4.0 kg mass is equal to 22 m/s.

What is Newton's second law of motion?

According to Newton’s second law of motion, the force acting on the object equals the mass of that object times its acceleration for a constant mass.

The acceleration of an object depends on two variables, one is the mass of the object and another is the net force acting. The acceleration of an object is directly proportional to the force acting on the body and inversely proportional to its mass.

The equation of Newton’s second law can be represented as follows:

F = ma  

or, a = F/m

Given, the initial velocity of the mass, u = 10m/s

The mass, m = 4.0 Kg

The force acting on the mass, F = 16 N

The acceleration of the mass will be: a = F/m

a = 16/4 = 4 m/s²

From the 1st equation of motion: v = u + at

The velocity after t = 3 sec can be calculated:

v = (10) + (4) × (3)

v = 10 + 12

v = 22 m/s

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Why is no image formed when an object is at the focal point of a converging lens?

Answers

Answer:

the refracted rays neither converge nor diverge. After refracting, the light rays are traveling parallel to each other and cannot produce an image.

Explanation:

A point source of light is located at the bottom of a steel tank, and an opaque circular card of radius is placed horizontally over it. A transparent fluid is gently added to the tank so that the card floats on the fluid surface with its center directly above the light source. No light is seen by an observer above the surface until the fluid is deep. What is the index of refraction of the fluid

Answers

start by using the addition as a sign and use multiplying

. A box is pushed across the floor for a distance of 5 meters with a force of 50 Newtons in 5 seconds.
a. How much work is done?



b. What is the power?

Answers

Answer:The total amount of work is

W = F × s (force x distance)

Explanation:   Explanation:

W

=

50

N

×

5

m

=

250

N

m

=

250

J

Done in 5 seconds the power is

p

=

W

t

where

t

=time

p

=

250

J

5

s

=

50

J

/

s

=

50

W

The work done in pushing the box is 250J b. The power is 50W.

What is Work done?

When a force is applied to a body and the body undergoes a displacement we say that work is done. So, mathematically we can write work done as product of force and displacement. Its unit is joule(J).

W = F x D

where, F = force, D = Displacement

What is power?

Power is the rate of doing work . If work is done by an appliance or object in less time then we can say that it has more power .Its unit is watt(W). Power is expressed as ,

P = W / t

where, W = work done ,t = time taken

To calculate the work done we use the formula

W = F X D

Given here, F = 50N displacement =5m

So, work done = 50 x 5 = 250J

Hence the work done in pushing a box across the floor for a distance of 5 meters with a force of 50 Newtons in 5 seconds is 250J.b. The power is given by ,P = W /t here, work done W = 250Jtime taken t = 5s

So, power is P = 250/5 =50W

Hence the solution of the question is

a. The work done in pushing the box is 250J

b. The power is 50W

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3. An airplane is flying at 10 km altitude in the standard atmosphere. The internal pressure of the aircraft interior is 100 kPa. Estimate the outward force on the window. The window is flat and has an elliptical shape with lengths of 300 mm along the major axis and 200 mm along the minor axis.

Answers

Answer:

The correct response will be "13.755 kN".

Explanation:

According to the question,

The given values are:

a = 300 mm

i.e.,

  = 0.3 cm

b = 200 mm

i.e.,

  = 0.2 dm

Internal pressure,

[tex]P_{in}=100[/tex]

Now,

The area of the elliptical shape window will be:

⇒  [tex]A = \pi ab[/tex]

On substituting the values, we get

⇒      [tex]=3.14\times 0.300\times 0.200[/tex]

⇒      [tex]=0.1885 \ m^2[/tex]

By using the table,

At 10 km, the atmospheric pressure will be

⇒  [tex]p_o=27.03 \ kPa[/tex]

Now,

The outward force will be:

⇒  [tex]F_{net}=p_{in}A-p_{0}A[/tex]

⇒          [tex]=(p_{in}-p_{0})A[/tex]

⇒          [tex]=(100-27.03)\times (0.1885)[/tex]

⇒          [tex]=13.755 \ kN[/tex]

Samir wants to be a doctor like both of his parents when he gets older he never thought of doing anything else which of the following best explains Samir decision ?

Answers

Where is the following

Which direction do longitudinal waves travel?

Answers

Answer:

If the particles of the medium vibrate in a direction parallel to the direction of propagation of the wave, it is called a longitudinal wave. In longitudinal waves, the particle movement is parallel to the direction of wave propagation.

Explanation:

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Which of these is one of the five determinants of health?
A. The gender of your doctor
B. Your access to health services
C. The type of sport you play
D. The amount
your insurance deductible

Answers

Answer:

B

Explanation:

Due to the earth's rotation, a person would be traveling faster at the equator than they would at a position halfway from the equator to the North Pole.

Answers

Answer:

False

Explanation:

It is actually the exact opposite.

Answer:

True.

Explanation:

Because the Earth's rotation causes it to bulge at the equator, the circumference of the Earth is greatest at the equator. This means that a person at the equator would have to travel a greater distance in a given amount of time than a person at a position closer to the poles. Therefore, a person at the equator would be traveling faster than a person at a position closer to the poles.

The universe could be considered an isolated system because (2 points)

A: many people think that no energy or matter exists outside the universe

B: energy and matter are created in the universe and flow freely into and out of the universe

C: energy is created outside the universe and matter is created within the universe

D: energy is created in the universe and matter is transferred out of the universe

Answers

the answer is B ......

PLEASE HELP

name 4 fundamentally different options for cooking a chicken​

Answers

Answer:

roasting,

broiling,

pan-broiling,

pan-frying,

grilling.

Explanation:

good luck

Answer:

Explanation:

1. Stir frying

2. Pan frying

3. Grilling /BBQ

4. Baking/roasting

How do pigs mate with eachother?

Answers

They touch each other and make nuzzling a part of their courtship. During courtship, the boar may nudge and nuzzle the sow's flank, head, genital area and shoulders, showering her with his attention. The sow and boar sing to each other as they nuzzle and chase each other.

Answer:

Pigs enjoy touching each other and make nuzzling a part of their courtship. During courtship, the boar may nudge and nuzzle the sow's flank, head, genital area and shoulders, showering her with his attention. The sow and boar sing to each other as they nuzzle and chase each other.

Explanation:

wanna rp?

A gun is sounded and an echo received from a wall 6 seconds later. If the speed of sound is 330m/s, how far away is
the wall?

Answers

Answer:

Neither the source or wall is moving so the sound takes 3 sec to get to the wall and 3 sec to return

D = 3 * v = 330 m/s * 3 sec = 990 m

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Read the excerpt from H. G. Wells's The War of the Worlds. But, looking, I presently saw something stirring within the shadow: greyish billowy movements, one above another, and then two luminous diskslike eyes. Then something resembling a little grey snake, about the thickness of a walking stick, coiled up out of the writhing middle, and wriggled in the air towards meand then another. How does the author create an aesthetic impact in the excerpt? through realistic dialogue through a comforting tone through scientific explanation through colorful description Ima die why should i die Which sentence best uses a split infinitive to clearly emphasize the message of safe driving?Before getting behind the wheel, young drivers must remember not to text.O Young drivers must remember to fully narrow in their focus when they get behind the wheel.O Young drivers must remember to always turn off cell phones before getting behind the wheel.O When driving a car, young drivers need to completely ignore their cell phones. Why can the Haitian Revolution, even more so than the American Revolution and the French Revolution, be seen as a turning point in the history of the Atlantic World? Helppppp plzzzzzzzzzzz Terrance wants to learn more about World War I. He would find mostof the informationA. In an article about the National Guard BureauB. On a Web site about the U.S during the 1920sC. In a history bookD. On a map of EuropeSUBMIT in order to palpate an apical pulse when performing a cardiac assessment, where should the nurse place the fingers? What was a result of the end of the Yuan Dynasty? Brust takes his cut (one-fourth) of the Algebros profit from selling fidget spinners to the store and bought 10 donuts for $12. He came home with more than $3.00.a.) Write an inequality that represents the situation and use it to find out how much money the Algebros had made from selling fidget spinners. Make sure you define your variables.(Thank you so much if you help me! I will mark you brainliest and give thanks) POETRY 1.) In a poem, what are 2 lines combined called?How about 3 lines?4 lines?5 lines?6 lines?8 lines? 2.) The use of words to suggest the opposite of their meaning or what is unexpected is called what? 3.) Objects, characters, or other concrete representation of ideas are called what? 4.) A 14-line poem with a set rhyme scheme is called what? IN WHAT WAY CAN THE EXECUTIVE BRANCH LIMIT THE POWER OF THE LEGISLATIVE BRANCH? *A- THE PRESIDENT CAN VETO A BILL PROPOSED BY CONGRESSB- THE PRESIDENT CAN REFUSE TO FOLLOW THE CONSTITUTIONC- THE PRESIDENT CAN PROPOSE AMENDMENTS TO THE CONSTITUTIOND- B AND CWHICH IS AN EXAMPLE OF THE WAYS IN WHICH CONGRESS CAN LIMIT THE POWER OF THE PRESIDENT? *A- CONGRESS CAN PASS NEW GOVERNMENT SPENDING LAWSB- CONGRESS CAN CHOOSE SUPREME COURT JUSTICESC- CONGRESS CAN REFUSE TO FOLLOW THE CONSTITUTIONWITH A 2/3 MAJORITY IN THE HOUSE OF REPRESENTATIVES AND THE SENATE, D- D- CONGRESS CAN OVERTURN A PRESIDENTIAL VETO What is the sum of 1 and 2? what is the answer to this quisten Read this sentence from Paragraph 4 of the passage.I cant imagine how far gone I must have seemed to her, but Ill never forget what she said as I prodded the chocolate mass parading as cake on my tray.Which word has the most similar meaning to prodded in this sentence?A) shovedB) pokedC) touchedD) ate(i have an answer but im just checking if im right) how would you solve this, need help Arrange the following sentences in the correct order for the introductory paragraph of an argumentative essay. Children under the age of twelve should be not be allowed to play tackle football. Americans value their children much more than a game, don't they? Third, although there have been changes made to the equipment and rules of tackle football, it is still not safe enough. Second, there are many safer options than tackle football for children who love athletics. First, since the discovery of the degenerative brain disease, C.T.E., which is caused by repetitive hits to the head, the people who support tackle football have been put on the defensive-- and for good reason. Worth 35 pointsWhich of the following describes characteristics that impact the amount of ozone pollution near Earth's surface?I. A region's topographyII. An area's weather patternsIII. Human activities I and II II and III I and III I, II, and III look at the screenshot i posted :) i need help Choose all of the possible causes of structural unemploymentes)changes in seasonsB)changes in technologyincrease in global competitionD)changes in personal career choicesE)changes in required training or education Explain how you could use the construction tool or a compass and straightedge to create a line segment that is twice as long as .