A stationary siren creates an 894 Hz
sound. When a motorcyclist is driving
toward it, she hears a 926 Hz sound
How fast is she driving?
(Speed of sound = 343 m/s)
(Unit = m/s)​

Answers

Answer 1

Answer:

12.3 m/s

Explanation:

The Doppler equation describes how sound frequency depends on relative velocities:

fr = fs (c + vr)/(c + vs),

where fr is the frequency heard by the receiver,

fs is the frequency emitted at the source,

c is the speed of sound,

vr is the velocity of the receiver,

and vs is the velocity of the source.

Note: vr is positive if the receiver is moving towards the source, negative if away.

Conversely, vs is positive if the receiver is moving away from the source, and negative if towards.

Given:

fs = 894 Hz

fr = 926 Hz

c = 343 m/s

vs = 0 m/s

Find: vr

926 = 894 (343 + vr) / (343 + 0)

vr = 12.3

The speed of the car is 12.3 m/s.


Related Questions

The law of conservation of momentum states that the total momentum of interacting objects does not _____. This means the total momentum _____a collision or explosion is equal to the total momentum _____ a collision or explosion.

Answers

Answer:

The law of conservation of momentum states that the total momentum of interacting objects does not change. This means the total momentum before a collision or explosion is equal to the total momentum after a collision or explosion.

Answer:

The answer is

Explanation:

Change. Does not change.means.

Hope this helps....

Have a nice day!!!!


The velocities of light in air and glass are 3.0 x 10^8ms and 2.0×10^8ms respectively. If the angle of refraction is 30°, the sine of the angle of incidence is?
Pls help​

Answers

Answer:

0.75

Explanation:

[tex]refractive \: index \: = \frac{3.0 \times {10}^{2} }{2.0 \times {10}^{2} } [/tex]

= 1.5

[tex]refractive \: index = \frac{ \sin(angle \: of \: incidence) }{ \sin(angle \: of \: refraction) } [/tex]

[tex]1.5 = \ \frac{ \sin(i) }{ \sin(30) } [/tex]

1.5 × ½ = sin(i)

[tex] \sin(i) = 0.75[/tex]

element X has two isotopes: X-27 and x-29. x-27 has an atomic mass of 26.975 and a relative abundance of 82.33%, and X-29 has an atomic mass of 29.018 and a relative abundance of 17.67%. calculate the atomic mass of element X. show your work

Answers

Answer:

27.34 (no unit)

Explanation:

26.975*82.33%+29.018*17.67%

=27.34

A dog is 10 m from a cat, whose speeds are 6 and 5 m / s, respectively. What time does the dog require to catch the cat?

Answers

Answer:

10 seconds

Explanation:

because the cat is moving one m/s slower than the dog, the dog has a relative speed of 1 m/s. 10 meters would take 10 seconds for the dog to cover

Which of the following will cause an induced current in a coil of wire? A. A wire carrying a constant current near the coil B. A magnet being moved into or out of the coil C. The constant field of the Earth passing through the stationary coil D. A magnet stationary resting near the coil

Answers

Answer:

B. A magnet being moved into or out of the coil

Explanation:

Faraday law of electromagnetic induction states that when there is change in flux , an emf is produced . Among the given instances , only in case of B , flux is changing . So current will be induced in the coil . We shall see how it takes place .

A wire carrying constant current will produce magnetic flux in nearby coil but there is no change in flux because current as well as position of wire with respect to coil are  not changing  .

Passing of magnetic field through a stationary coil produces flux in the coil but here too there is no change in flux so no current will be induced .

A magnet positioned near a coil creates magnetic flux in the coil but the magnitude of flux remains constant so no change in flux and no creation of induced current .

How is heat transferred during thermal conduction? Through direct contact of particles Through electromagnetic waves Through motion of hot and cold liquid Through the rising of a warm gas

Answers

Answer:

Through direct contact of particles

Explanation:

Heat is transferred in the following ways listed below

1. Conduction(Through direct contact of particles )

2. Convection(Through motion of hot and cold liquid )

3. Radiation(Through electromagnetic waves Through the rising of a warm gas )

1. Conduction: This has to do with the transfer of heat from one medium to another having direct contact with each other, the medium can either be solid or liquids

2. Convection: Has to do with the transfer of heat energy via molecules of the liquids in motion with different or varying temperature gradients

3. Radiation: Mostly occurs in gases, it is the transfer of energy through waves

When astronauts are on spacewalks outside of the International Space Station, they must use a communication system with radio waves to be able to talk to each other. Explain why focusing on the difference between sound and light waves

Answers

Light waves are electromagnetic waves while sound waves are mechanical waves. Light waves are transverse while sound waves are longitudinal. Light waves can travel in vacuum. Sound waves require a material medium to travel, and hence, cannot travel in vacuum.

They make use of radio waves. Radio waves signal are sent their headsets that in turn translates the signal in the form of sound. While communicating with people on Earth – the radio waves are transmitted which in turn are transformed to sound wave by a radio set. Radio waves comes from the light spectrum called Electromagnetic Spectrum and thus they are light waves. Unlike sound, light waves doesn’t need a medium to travel and it is for this reason that the sun ray travels through space to the Earth

We all know who was the first man that landed on moon? But were the first words ever heard in space?

It was the announcement of landing that was said by Neil Armstrong: “Lunar Module has landed on moon”

Answer: Light waves are electromagnetic waves while sound waves are mechanical waves. Light waves are transverse while sound waves are longitudinal. Light waves can travel in vacuum. Sound waves require a material medium to travel, and hence, cannot travel in vacuum.

Explanation:

a 2-n force is applied to a spring, and there is displacement of 0.4 m. how much would the spring be displaced if a 5-n force was applied?

Answers

Answer:1m

Explanation:

2n=0.4m

5n=?

5n×0.4/2n=1m

This force governs atomic decay.

Answers

Answer:

The weak force governs the decay of a neutron into a proton (a process known as beta decay). The strong force binds quarks together into protons and neutrons (the residual strong force holds protons and neutrons together in the nucleus). Gravity governs the motion of an apple falling from a tree.

Explanation:

Answer:

Weak Nuclear force

1. If a car travels 400m in 20 seconds how fast is it going?
2. If you move 50 meters in 10 seconds, what is your speed?
3. You arrive in my class 45 seconds after leaving math which is 90 meters away. How fast did you travel?
4. A plane travels 395,000 meters in 9000 seconds. What was its speed?
5. It takes Serina 0.25 hours to drive to school. Her route is 16 km long. What is Serina's average speed on her
drive to school?

Answers

Answer:

1) 20 m/s

2) 5 m/s

3) 2 m/s

4) 395,000m/9000s

5) 16 km/0.25h

Explanation:

i dunno

claculate the pressure exerted by the water on the bottom of a deep dam of 12m from its surface .(density of water =1000kg/m sqare)​

Answers

Explanation:

We know that,

[tex]hydrostatic \: pressure (p) = \alpha hg [/tex]

Where,

[tex] \alpha = density \: of \: water \: = 1000[/tex]

h = Height at which pressure is to be calculated

[tex]p = 1000 \times 12 \times 9.8 = 117600 \: [/tex]

Question 14 of 30
A bundle of roofing shingles slides off a roof and is falling to the ground. As it
falls, what kind of energy does it possess?
O A. Kinetic only
O B. Potential only
O C. Radiant
D. Kinetic and potential​

Answers

Answer:

kinetic and potential

with solutions please give with solution
if u give me with solution I will mark in brainlist​

Answers

Answer:

Magnitude of Force : 0.8 N

Explanation:

We know that the velocity of this particle changes from 15ms⁻¹, or in other words 15m / s, to the respective velocity 25m / s over the course of 2.5 seconds. Given this information we can determine the acceleration of the particle,

a = v₁ - v₂ / t = 25 - 15 / 2.5 = 10 / 2.5 = 4m / s²

Knowing the acceleration we can calculate the magnitude of the force using the formula f = ma - Newton's second law of motion,

f = m [tex]*[/tex] a = 200g [tex]*[/tex] 4m / s² = 800 g [tex]*[/tex] m / s²

Remember however that Newtons are in the standard units kg [tex]*[/tex] m / s². Therefore we have to convert 800 g to kg to receive our solution,

800 g = 800 / 1000 kg = 0.8 kg,

Magnitude of Force = 0.8 N ; Solution = Option B

A series combination of 12 Ω and 3 Ω is connected in parallel with another series combination of 6 Ω and 3 Ω. If a potential difference of 4 V is applied across it find the i) current is drawn from the battery ii) current through 12 Ω resistor (iii)potential difference across 6 Ω resistor?

Answers

Answer:

a) 0.73A

b) 0.23A

c) 2.76V

Explanation:

We need to first resolve the two resistors in series. The resistors in series are

12 Ω and 3 Ω  AND 6 Ω and 3 Ω

For  12 Ω and 3 Ω in series, total effective resistance =  12 Ω + 3 Ω = 15 Ω

For  6 Ω and 3 Ω in series, total effective resistance =  6 Ω + 3 Ω = 9 Ω

Since the equivalent series resistors i.e 15Ω ND 9Ω are connected in parallel, the total effective resistance Rt will be expressed as;

1/Rt = 1/15+1/9

1/Rt = (3+5)/45

1/Rt = 8/45

Rt = 45/8 Ω

a) If a potential difference of 4 V is applied across it, the total current I in the circuit can be derives using the ohms law.

According to the law E = IRt

Given E = 4V, Rt = 45/8

I = E/Rt

I = 4/(45/8)

I = 4 * 8/45

I = 32/45

I = 0.73A

Hence, the current drawn from the battery is 0.73A

b) Before we can calculate the current in the 12Ω resistor, we need to calculate the current in the equivalent resistance of 15Ω(sum of 12Ω and 3Ω)

Current in the 15Ω resistor = Voltage across the 15Ω resistor/Resistance

Current in the 15Ω resistor = 4/15

Current in the 15Ω resistor = 0.27A

Since the same current flows in a series connected resistors, hence the correct in the 12ohms resistor is also 0.27A.

c) Before we can calculate the pd across the 6ohms resistor, we need to know the voltage across the effective resistance of 9ohms(6ohms+3ohms). The pd across the 9ohm resistance will be the same as the source voltage i.e 4Volts.

We will need to share this 4volts between the 6ohms and the 3ohms using ohms law.

According to the law, V = IR

For the 6ohms resistor, voltage across it will be;

V = (0.73-0.27)×6

V= 0.46×6

V = 2.76Volts.

Hence the voltage across the 6ohms resistor is 2.76V.

A cell membrane has a thickness of about 7 nm. How many cell membranes would it take to make a stack 2.3 in high?

Answers

Answer:

There are 8345714 cell membranes.

Explanation:

It is given that,

The thickness of a cell membrane is 7 nm

We need to find the number of cell membranes would it take to make a stack 2.3 inches high.

Firstly, the units must be same i.e. converting 2.3 inches to m

1 inch = 0.0254 m

2.3 inches = 0.05842 m

Let there are n number of cell membranes. So,

[tex]n=\dfrac{\text{stack height}}{\text{1 membrane thickness}}\\\\n=\dfrac{0.05842}{7\times 10^{-9}}\\\\n=8345714.28[/tex]

or

n = 8345714 cell membranes

Will mark as BRAINLIEST.......

The position vector is given by vector r= 5t² I cap + 2 t³ j cap + 2 k cap. Find it's velocity and acceleration at t=2s.

Answers

Answer:

We have the position vector given in terms of time t. r(t) = t^3*i + t^2*j

To find the velocity vector we have to differentiate r(t) with respect to time.

r'(t) = 3t^2*i + 2t*j

The vector representing acceleration is the derivative of the position vector

r''(t) = 6t*i + 2*j

When time t = 2.

The velocity vector is 3*2^2*i + 2*2*j

=> 12*i + 4*j

The speed is the absolute value of the velocity vector or sqrt(12^2 + 4^2) = sqrt (144 + 16) = sqrt 160

The acceleration vector is 6*2*i + 2*j

=> 12*i + 2*j

The required acceleration at t=2 is 12*i + 2*j and the speed is sqrt 160.

Explanation:

Can I have thx and brainliest?

This is the written answers to find the velocity and acceleration of r

The particles of a GAS within a closed container will collide with the container walls, exerting a FORCE. The force per unit of AREA is known as what?

Answers

Answer:

Pressure

Explanation:

One of the theories propounded by the Kinetic molecular theory, and which also provides an explanation of the several gas laws, is the statement that the gas molecules in a container, travel in straight lines and are in constant collision with themselves and the walls of the container, thus exerting force. This force is the pressure which is defined as the force per unit area.

There is no loss of energy in the collisions involving the gas molecules and that is why their movement can be described as elastic. The descriptions of the behavior of gas molecules in the Kinetic Molecular Theory, give rise to Charles law, Boyle's Law, Avogadro's Laws, Dalton's Law, and Amonton's Law.

Answer:

The pressure

Explanation:

Molecules of gases are constantly in motion, colliding with the walls of their container. This constant collision impacts force on the walls of the container, which depends on the speed with which the molecules are moving. The speed with which these molecules travel depends on the average kinetic energy of the molecules, which is proportional to the temperature.

This force when exerted per unit area is the pressure the gases exert on the walls of the container.

A control clinic offers a program that guarantees a weight loss of up to 0.46 kg in one week. Express the weight loss in a ratio of milligrams per second.

Answers

Answer:

0.76 mg/s

Explanation:

0.46 kg/week × (1 week / 7 days) × (1 day / 24 hrs) × (1 hr / 3600 s) × (1000 g/kg) × (1000 mg/g) = 0.76 mg/s

if a direction is somewhere between North and East it is measured in _____?

Answers

Answer:

degrees

Explanation:

If a direction is somewhere between north and east, it is measured in degrees.

This measurement will be possible thanks to the existence of geographical coordinates that are some 'imaginary lines' that help us find our location on the earth's surface. These lines are called latitude and longitude, both of which are measured in degrees.

It is like a sea battle game where you have to combine the rows and columns in order to identify where the targets are located. Geographic coordinates work the same way, you must combine the rows and columns of the planisphere to identify the locations of the planet. So the lines would be the latitudes and the columns the longitudes.

Which is the SI symbol for volume? m g L K

Answers

Common symbol of the volume (L)

Answer:

the answer is c.L

Explanation:

What is the cat's displacement t=0.5s to 1.5s,

Answers

Answer:

3.75m

Explanation:

area under graph

5+2.5=7.5

7.5/2=3.75

3.75x0.5=1.875

1.875x2=3.75m

Astronauts train for space flight in a centrifuge,which consists of a rotating arm with a cab at the outer end of thearm. The arm, which has a length of 58 feet, is revolved about thecenter of the centrifuge. An astronaut sits in the cab, which is thenrotated 50 times per minute. To the nearest hundred feet, how fardoes the astronaut travel in one minute?

Answers

Explanation:

We know that,

[tex]v = rw[/tex]

Where, v = tangential velocity (m/sec)

r = radius = 17.67 m

w = angular velocity = 0.83 revs/ sec

v = 14.66 m/sec

Distance in one minute = 879.6 m

= 2885.82 feet

An ideal gas is enclosed in a piston-cylinder apparatus with the piston being freely movable. Given that LaTeX: \DeltaΔE is positive and LaTeX: \DeltaΔH is negative following a process, ____ the system absorbs heat and expands during the process. the system absorbs heat and contracts during the process. the system loses heat and expands during the process. the system loses heat and contracts during the process. the system loses heat but neither expands nor contracts during the process.

Answers

Clear question is;

An ideal gas is enclosed in a piston-cylinder apparatus with the piston being freely movable. Given that ΔE is positive and ΔH is negative following a process,

pick one

A) the system absorbs heat and expands during the process.

B) the system absorbs heat and contracts during the process.

C) the system loses heat and expands during the process.

D) the system loses heat and contracts during the process.

E) the system loses heat but neither expands nor contracts during the process.

Answer:

Option A is correct.

Explanation:

In thermodynamics, when the change in energy which is ΔE of a system is positive, it means that the system is undergoing an endothermic process. An endothermic process is simply one where heat is absorbed from the surroundings

Now, when change in enthalpy which is ΔH is negative, it means that it's an exothermic reaction. Exothermic means it releases heat to the surroundings. This means work is positive because the system does work on the surroundings. Thus it will expand.

So the correct answer is;

heat is absorbed from the surroundings and will expand during the process.

A drone has been designed that can do monitoring and surveillance at considerable heights due to its light weight of 0.800 kg. For this purpose, they are doing a test to determine its maximum height and they make it start in a vertical direction, using its thrusters it manages to achieve a thrust of 35.0 N during the first 6.00 s. until the battery runs out. What was the maximum height that the drone reached?

Answers

Answer:

2660 m

Explanation:

Sum of the forces in the first 6.00 s:

∑F = ma

F − mg = ma

35.0 N − (0.800 kg) (10 m/s²) = (0.800 kg) a

a = 33.75 m/s²

The height it reaches during this time is:

Δy = v₀ t + ½ at²

Δy = (0 m/s) (6.00 s) + ½ (33.75 m/s²) (6.00 s)²

Δy = 607.5 m

The velocity it reaches is:

v = at + v₀

v = (33.75 m/s²) (6.00 s) + 0 m/s

v = 202.5 m/s

After the battery runs out, the drone is in free fall.  At the highest point, the velocity is 0.  The height at this point is:

v² = v₀² + 2aΔy

(0 m/s)² = (202.5 m/s)² + 2 (-10 m/s²) (h − 607.5)

h ≈ 2660 m

Which statement about the dark nebulae is true? Group of answer choices They can be penetrated only with longer wavelengths such as radio and infrared. They block the vast majority of radio waves from our Galaxy. Hydrogen and helium are the chief absorbing and scattering agents. They can be penetrated only with shorter waves, such as UV and x-ray. Only one is known to exist.

Answers

Answer:

They can be penetrated only with longer wavelengths such as radio and infrared.

Explanation:

A dark nebula can be defined as an interstellar cloud that is so dense as a result of high concentration of gas and dust and as such it obscures the visible wavelengths of light from stars behind it, thus appearing completely opaque (dark patch) in front of a bright emission nebula or in regions having  plenty stars.

Hence, dark nebulae can be penetrated only with longer wavelengths such as radio and infrared light because they cannot be absorbed by the dust layers or particles coated with frozen carbon monoxide and nitrogen residing in the dark nebulae.

Millimeters, centimeters, meters,
kilometers, inches, feet, and
miles are all examples of


plz help

Answers

Millimeters, centimeters, meters, kilometers, inches, feet, and miles are all part of the metric system used in the US.

Millimeters, centimeters, meters, kilometers, inches, feet, and miles are all examples of unit of length like: distance between two points  and displacement of any object.

What is unit?The quantity with a constant magnitude that is used to measure the magnitudes of other quantities of the same type is referred to as a unit in physics.The formula:  physical quantity = numerical value × unit. can be used to determine a physical quantity's magnitude.A unit shouldn't alter as time or environmental factors like pressure and temperature change.It ought to be precisely defined.It need to be readily available and repeatable.

Meter is  a Si unit of length whereas centimeter is CGS unit of length and  Feet is FPS unit of lengths. Another units are also useful in measuring lengths.

Learn more about units here:

https://brainly.com/question/12750330

#SPJ2

Question 5
Calculate the kinetic energy of a car (m - 800 kg) moving at 15 m/s. Write your answer to the nearest whole number in the blank space
provided. Only write the numerical value of the answer without units. Do not leave any space in between numbers.
Answer: Joules


Answers

Answer:

90,000

Explanation:

[tex]m =800kg\\v = 15\\\\K.E = \frac{1}{2}mv^2\\ K.E= \frac{1}{2} \times 800\times 15^2\\= 400 \times 225\\= 90000 joules\\= 90 kilojoules[/tex]

Please give best dialogue in photo that is attached And you are marked as Brainliest

Answers

Answer:

The correct answer is

Explanation:

Character 1: Why are these comic books so hard to read? Can u read them?

Character 2: No it's easy to read Tigger. It's because you are an animal an I am a human being. U don't know how to read.

Hope this helps....

Have a nice day!!!!

Answer:

Dialogue 1:

Hey buddy! Can you tell me what is written in this book? Its really hard to read:(

Dialogue 2:

Yeah! Its a story about a friendly tiger! And it is hard for you to read cause you don't know how to read.

Tip:

Try to make it more engaging  :)

What is the electric force acting between two charges of 0.0072 C and -0.0060 C that are 0.0040 m apart?

Answers

Answer:

Fe = 2.4 × 10^10 N

Explanation:

Given the following :

q1 = charge 1 = 0.0072 C = positive direction

q2 = charge 2 = 0.0060 C = - ve direction

r = distance = 0.0040

Using the relation :

Fe = K(q1q2) /r^2

Where K = columb's constant = 9×10^9 Nm^2/C^2

Fe = electric force

Fe = 9×10^9(0.0072 * 0.0060) / 0.0040^2

Fe = [9×10^9 (0.0000432)] / 0.000016

Fe = 388,800 / 0.000016

Fe = 24300000000

Fe = 2.43 × 10^10 N

Help uhh i need to know this answer

Answers

Answer:

Explanation:

2. 330.63 ft because v*t=d and 3.09*107=330.63

3. 4.2 because 10/2.4=4.1666

4. 130 miles because 2 hours times 65mph= 130

5. 62.3 seconds because 480000/7700=62.33766233

8. 60 meters, because 0.5 *120 (because 2 minutes converted to seconds is 120) is equal to 60.

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how are different religions interdependent? Sex ratio is defined as the number of females per 1000 males in the population. Find the sex ratio if there are 3732 females per 4000 males in a town. solve 3(x +15) 5(x+2) + 15 Which conclusion can be drawn from the experimental observation that a single strand of DNA contains 2100 dA residues and 1800 dT residues? what is the prime factorization of 430 URGENT! GIVING BRAINLIEST AND 18 POINTS. How did Constantine promote the expansion of Christianity? (A) He required Roman citizens to convert to Christianity. (B) He named the Roman capital to honor the Christian God. (C) He built Christian churches throughout the Roman Empire. (D) He made Christianity the official religion of the Roman Empire. Mary Martin, the owner of Martin Consulting, Inc., started the business by investing $48,000 cash. Identify the general journal entry below that Martin Consulting, Inc. will make to record the transaction. A Cash 48,000 Increased Equity 48,000 B Investments 48,000 Cash 48,000 C Cash 48,000 Common stock 48,000 D Common stock 48,000 Cash 48,000 E Investments 48,000 Common stock 48,000 Expert Answer Can someone please explain this to me? I dont understand it at all Figure B is a scaled copy of Figure A. What is the scale factor from Figure A to Figure B? Plants respond to changes in their environment. They detect gravity, light, touch, and seasonal changes, and respond to these stimuli in many ways. Which statement best explains this flexibility in response? A) Phenotypes are controlled by one gene that codes for multiple regulatory proteins. B) The genes that regulate plant responses can be expressed in different ways. C) The genes that regulate plant responses can mutate to adjust to environmental changes. D) Phenotypes control the genotypes of individuals, determining plant responses. Please i need help !!! External government debt is: Multiple Choice government debt owed to individuals in foreign countries. government debt owed by one branch of the government to another. government debt owed to its own citizens. debt that individuals in foreign countries owe to the U.S. government. A research worker gave a scholastic aptitude test to a sample of eighth graders. Then he correlated the aptitude test scores with the chronological ages of the subjects. He found a correlation of - .42. How should this result be interpreted? PLEASE HELP, WILL GIVE BRAINLIEST IF CORRECT!!!! (08.06 MC) Mike and his friends bought cheese wafers for $2 per packet and chocolate wafers for $1 per packet at a carnival. They spent a total of $25 to buy a total of 20 packets of wafers of the two varieties. Part A: Write a system of equations that can be solved to find the number of packets of cheese wafers and the number of packets of chocolate wafers that Mike and his friends bought at the carnival. Define the variables used in the equations. (5 points) Part B: How many packets of chocolate wafers and cheese wafers did they buy? Explain how you got the answer and why you selected a particular method to get the answer. (5 points) Observation: The bee's wings are moving very fast.The bee's wings are much smaller than its body.Which question is based on these observations?A. Do bees fly faster before or after feeding?B. How are bees affected by weather changes?O C. Do bees prefer warm or cold climates?O D. At what time of day do bees eat? From among them, select the one who you think did the most to help de-escalate or end the Cold War. Remember, the person you select should exemplify the leadership qualities of negotiation and restraint. Write the name of the leader you chose in the answer space. 12 2x= -2(y x)-2x = -2(y x) 12x= (y - x) + 6 In what ways do we travel across the country? What ways do you think are best fortransporting people? Goods? The diameter of Earths moon is on average m. Use the formula to find the approximate surface area. (Use 3.14 for the value of .) (SHOW WORK) Central to agency theory is the concern with problems that can arise between the principals who are the owners of the firm and the agents who are the people who are paid by outside consultants to perform a job on their behalf.a. Trueb. False