Answer:
(a) the observed frequency is 200 Hz
(b) the observed frequency is 188 Hz.
Explanation:
speed of the truck, Vs = 27 m/s
frequency of the truck as it approaches, Fs = 185 Hz
(a) Apply Doppler effect to determine the frequency you will hear.
As the truck approaches you, the observed frequency will be higher than the source frequency because of decrease in distance.
[tex]F_s = F_o [\frac{V}{V_S + V} ][/tex]
Where;
Fo is the observed frequency which is the frequency you will hear.
V is speed of sound in air
[tex]F_s = F_o [\frac{V}{V_S + V} ]\\\\185 = F_o [\frac{340}{27 + 340} ]\\\\185 = F_o (0.926)\\\\F_o = \frac{185}{0.926}\\\\F_o = 199.78 \ Hz[/tex]
[tex]F_o = 200 \ Hz[/tex]
(b) Apply the following formula for a moving observer and a moving source;
[tex]F_o = F_s[\frac{V-V_o}{V} ](\frac{V}{V-V_S} )[/tex]
The observed frequency is negative since you are driving away from the truck and the source frequency is also negative since it is driving towards you.
[tex]F_o = F_s[\frac{V-V_o}{V} ](\frac{V}{V-V_S} )\\\\F_o = 185[\frac{340-22}{340} ](\frac{340}{340-27} )\\\\F_o = 185(0.9353)(1.0863)\\\\F_o = 188 \ Hz[/tex]
Select the correct answer.
Derick has been working as a first responder since many years. His primary responsibility at a crime scene is to question witnesses and gather
useful information from the scene. Which of these first responder career roles does Derick fit into?
OA paramedic
OB. police officer
Oc. fire truck driver
OD. firefighter
Answer:
Police officer
Explanation:
Because police officers wants to gather information on what happens and question people to know everything. That is what Derick is doing
how is red shift evidence of the big bang
it implies our universe is expanding
it implies our universe is collapsing
it implies our universe is standing still
Answer:
it implies our universe is expanding
According to The Flash, The heroes top speed is Mach 3.3, or 2,500 miles per hour. How
long would it take for him to run around the planet? (circumference of the earth is
roughly 25,000 miles) *
Answer:
nearly 2 days or less hes fast but not that fast
Explanation:
but maybe he can run it in five minutes
Need help ASAP plsss
Write 5-6 sentences about
:how do parachutes work ??
A ripcord system pulls a closing pin, which releases a spring-loaded pilot chute, and opens the container; from which the parachute comes out.
If a skydiver is unable to open her/his parachute, an automatic activation device will automatically open the parachute.
A parachute works by forcing air into the front of it and creating a structured 'wing' under which the canopy pilot can fly. Parachutes are controlled by pulling down on steering lines which change the shape of the wing, cause it to turn, or to increase or decrease its rate of descent.
How do the potential and kinetic energy change as the sled moves down the slope?
IF YOU DID SLED WARS WORKSHEET HELP ME PLEASE
Answer:
when a sled is moving, the kinetic energy is changing beacuse of the speed and mass. its cause the sled to move, and changes because you aren't at a constant speed. potential energy changes when you get on. because you are adding more weight causing the gravity to change.
Pelican hunts fish in the water as th pelican the waters surface why must it aim for the fish in a slightly different place than where the fish appears to be located
The Pelican must aim differently than where the fish appears to be because light is refracted from air to water.
Refraction is the change in the direction of a wave at the interface between two media. The effects of refraction are easily seen when light is travelling from air to water hence objects are not really where they appear to be when viewed above the water surface.
Hence, the Pelican must aim differently than where the fish appears to be because light is refracted from air to water.
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You have to move your 100 N couch before a delivery company drops off your new one. Unfortunately your roommate is passed out on it. The coefficient of friction between the couch and floor is .43. It takes 250 N of force to get the couch moving. a) How much does your roommate weigh in Newton’s? b) After you get the couch moving it only takes 200 N to keep it moving at a constant speed, what is the coefficient of kinetic friction?
Answer:
a) Weight of Roommate = 481.4 N
b) μk = 0.34
Explanation:
a)
The force required to move the couch must be equal to the force of friction:
F = frictional force
F = μW
W = F/μ
where,
W = Total Weight of Couch and Roommate
F = Force Required start to move couch = 250 N
μ = coefficient of static friction between couch and floor = 0.43
Therefore,
[tex]W = \frac{250 N}{0.43}\\\\W = 581.4 N[/tex]
So, the total weight is given as:
W = Weight of Couch + Weight of Roommate
Weight of Roommate = W - Weight of Couch
Weight of Roommate = 581.4 N - 100 N
Weight of Roommate = 481.4 N
b)
Now, the force required to keep the couch moving can be given as equal to the kinetic friction force:
F = kinetic friction
F = μk*W
μk = F/W
where,
μk = coefficient of kinetic friction = ?
F = Force required to keep the couch moving = 200 N
Therefore,
μk = 200 N/581.4 N
μk = 0.34
A stiuden goes for a bike ride ayt 20 meters
What is unique regarding the abdominal muscle when is compared to other muscle in the body?
(A) it is a very large muscle
(B) it does not develop easily
(C) it can move the body either from the ribcage or the pelvis.
(D) it can get injured easily if you perform a lot os repetitions.
(E) none of the above
Define specific vision??
Answer:an inspirational statement of an idealistic emotional future
Explanation:
I don't know if it's right tho
Answer:
The document that state tge currentand future objectives of an organization.
What is the force (in Newtons, 1 Newton = 1Kgm/s2) required to accelerate a 1500 Kg car to 3 m/s2?
Answer:
F=4500N
Explanation:
F=m×g
F=1500kg×3m/s²
F=4500N
Answer:
F=4500N
Explanation:
F=m×g
F=1500kg×3m/s²
F=4500N
A Ferris wheel with 60 spokes has a diameter of 100 m. It makes one rotation every 60 seconds. Find the speed of the passengers when the Ferris wheel is rotating at this rate.
Answer:
The speed of the passengers is 5.24 m/s
Explanation:
Uniform Circular Motion
It occurs when an object in a circular path travels equal angles in equal times.
The angular speed can be calculated in two different ways:
[tex]\displaystyle \omega=\frac{v}{r}[/tex]
Where:
v = tangential speed
r = radius of the circle described by the rotating object
Also:
[tex]\omega=2\pi f[/tex]
Where:
f = frequency
Since the frequency is calculated when the number of revolutions n and the time t are known:
[tex]\displaystyle f=\frac{n}{t}[/tex]
The Ferris wheel has a diameter of 100 m and makes n=1 rotation in t=60 seconds, thus the frequency is:
[tex]\displaystyle f=\frac{1}{60}\ Hz[/tex]
The angular speed is:
[tex]\displaystyle \omega=2\pi \frac{1}{60} =\frac{\pi}{30} \ rad/s[/tex]
Now we calculate the tangential speed, solving this formula for v:
[tex]\displaystyle \omega=\frac{v}{r}[/tex]
[tex]v=\omega . r[/tex]
The radius is half the diameter, r=100/2=50 m:
[tex]\displaystyle v=\frac{\pi}{30} . 50[/tex]
Calculating:
v = 5.24 m/s
The speed of the passengers is 5.24 m/s
Suppose that the separation between two speakers A and B is 6.60 m and the speakers are vibrating in-phase. They are playing identical 126-Hz tones and the speed of sound is 343 m/s. An observer is seated at a position directly facing speaker B in such a way that his line of sight extending to B is perpendicular to the imaginary line between A and B. What is the largest possible distance between speaker B and the observer, such that he observes destructive interference
Complete question
The diagram for this question is shown on the first uploaded image
Answer:
The largest possible distance is [tex]e = 15.33 \ m[/tex]
Explanation:
From the question we are told that
The separation between Speaker at position A and B is AB = 6.60 m
The frequency of the tune which the speaker are playing is [tex]f = 126 \ Hz[/tex]
The speed of sound is [tex]v = 343 \ m/s[/tex]
Generally the wavelength of the tune playing is mathematically represented as
[tex]\lambda = \frac{v}{f}[/tex]
=> [tex]\lambda = \frac{343}{ 126}[/tex]
=> [tex]\lambda = 2.72 \ m[/tex]
Let the observer be at position D
Generally the distance A and is mathematically evaluated using Pythagoras theorem as
[tex]AC = \sqrt{AB ^2 + BC^2}[/tex]
Let BC = e
So
[tex]AC = \sqrt{6.60 ^2 + e^2}[/tex]
Generally the path difference between the first and the second speaker from the observer point of view is mathematically represented as
[tex]P = AC - BC[/tex]
=> [tex]P = \sqrt{6.60 ^2 + e^2} - e[/tex]
Generally the condition for destructive interference is mathematically represented as
[tex]P = (2n - 1 )\frac{\lambda}{2}[/tex]
Here n is the order of the fringe which is one
=> [tex]\sqrt{6.60 ^2 + e^2} - e = (2 * 1 - 1 )\frac{2.72}{2}[/tex]
=> [tex]\sqrt{6.60 ^2 + e^2} - e = 1.36[/tex]
=> [tex]6.60 ^2 + e^2 =( 1.36 +e)^2[/tex]
=> [tex]6.60 ^2 + e^2 =1.8496 + 2.72e +e^2[/tex]
=> [tex]e = 15.33 \ m[/tex]
A phosphodiester bond is used to:
A. Join glycerol to fatty acids
B. Join two nucleotides into a polynucleotide
C. Join two glucose molecules
D. Join two amino acids into a polypeptide
Answer:
A. Join glycerol to fatty acids
Explanation:
I majored in Physics.
Two disks are rotating about the same axis. Disk A has a moment of inertia of 3.4 kg m^2 and an angular velocity of 7.2 rad/s. Disk B is rotating with an angular velocity of -9.8 rad/s. The two disks are then linked together without the aid of any external torques, so that they rotate as a single unit with an angular velocity of -2.4 rad/s. The axis of rotation for this unit is the same as that for the separate disks. What is the moment of inertia of disk B
Answer:
I = 4.4 kg*m^2
Explanation:
As no external torques are present, total angular momentum must be conserved, as follows:[tex]L_{o} = L_{f} (1)[/tex]
The initial angular momentum of the two disks rotating separately, can be written as follows:[tex]L_{o} =I_{A} * \omega_{oA} + I_{B} * \omega_{oB} (2)[/tex]
Replacing by the givens, we get:[tex]L_{o} = 3.4kg*m2 * 7.2rad/s + I_{B} * (-9.8 rad/s) (3)[/tex]
The final angular momentum Lf, as the axis of rotation remains the same, is the product of the moment of inertia of both disks rotating as one, and the common angular velocity ωf, as follows:[tex]L_{f} = (I_{A} + I_{B}) *\omega_{f} (4)[/tex]
Replacing by the givens, we get:[tex]L_{f} = (3.4 kg*m2 + I_{B} ) * (-2.4 rad/s) (5)[/tex]
From (3) and (5), we can solve for IB, as follows:IB = 4.4 kg*m2Do YOU think aliens are real? HELP PLS
Which answer best displays Adam's use of the civic virtue "diversity"?
Diversity means something is benifical to an entire group.
Diversity means fair treatment of all people the
Answer:Yes
Explanation:yeah i think it could be possible because the universe is so far and wide its probably infinite and if we did i personally believe that we would be absolutely be annihilated by them because we would be so far behind technology wise we would have no use for the\
YOU FELL FOR IT FOOL THUNDER CROSS SPLIT ATTACK
a passenger of mass m on a Ferris wheel moves in a vertical circle of radius r with constant speed v assuming that the seat remains upright during the motion which is true about the force the seat exerts on the passenger at the top of the circle
the upward force is equal in magnitude to the passenger's weight
the upward force is greater in magnitude than the passenger's weight
the upward force is smaller in magnitude than the passenger's weight
the upward force is zero
Answer:
the upward force is equal to the passenger weight
The answer that is the truth about the force that the seat exerts on the passenger is the upward force is equal in magnitude to the passenger's weight.
Why the upward force is equal in magnitude to weight
The acting forces on the body has been said to be vertical. This implies that the upward force and the downward force of gravity are the same.
Using the second law of Isaac Newton, the downward direction of the forces would be ascertained.
Read more on force and magnitude here:
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Joe applies a force of 50 N to a box which has a mass of 15 kg. What is the acceleration of the box?
a.
Answer:
3.333 m/s^2
Explanation:
50/15 = 3.33 m/s^2
If forces acting on an object are unbalanced, the object could experience a change in ________.
mass, speed, or direction
negative acceleration or mass
direction, mass, or both
speed, direction, or both
D) Speed, direction, or both
Mass doesn’t just CHANGE like that.
What are some ways that the Greeks demonstrated their passion for public life?
Answer:
The Greeks had drama and arts competitions that were considered very popular, and important in society.
Explanation:
hope it helps!
Use the image below to answer the question.
What does the arrow 'B' represent?
Question 7 options:
wavelength
refraction
frequency
compression
identical spheres are dropped from a height of 100 m above the surfaces of Planet X and Planet Y. The speed of the spheres as a function of time is recorded for each planet in the graph
above. Which planet exerts the greater force of gravity on the sphere, and what evidence supports this conclusion?
A Planet X because its line has the greater area under it.
Planet X, because its line has the greater slope
Planet Y. because it falls for the smaller amount of time
Planet Y because the object's final speed is greater
Answer:
B. Planet X, because its line has the greater slope.
Explanation:
In a speed graph, acceleration is slope. A greater slope means a greater acceleration. According to Newton's 2nd law (F=mg), a greater acceleration means a greater force.
Planet X exerts the greater force of gravity on the sphere, because its line has the greater slope. Hence option B is correct.
What is Gravitational Force ?Gravitational force is force of attraction between two masses. Gravitational force(F) between two bodies is directly proportion to the product of masses(m₁,m₂) of two bodies and inversely proportional to square of distance(r) between them. mathematically it is written as,
F ∝ m₁.m₂
F ∝ 1/r²
F = G m₁,m₂÷r²
where G is gravitational constant, whose value is 6.6743 × 10⁻¹¹ m³ kg-1s⁻².
Force is expressed in Newton N in SI unit. its dimensions are [M¹L¹T⁻²].
This is analogous with coulomb's law which gives force between two charges.
if a planet has greater gravitational force(force of gravity), then body falls with greater speed as compare to other planet which is having less force of gravity. we can see in case of planet X there is greater speed as compare to plane Y in short time. Hence option B is correct.
To know more about Gravity :
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before leaving earth, the mass if an astronaut is measured to be 60kg. the astronaut lands on the moon and measures the acceleration of gravity to be 1.6 m/s^2. what is the mass of the astronaut at moon?
Answer:
The answer is 2,475$+948= add you will get the answer rn
The weight we experience on a surface is the product of our mass and acceleration due to gravity on that surface. The mass of the astronaut in earth was 60 kg . Then his mass at moon will be 9.76 kg.
What is gravitational force ?The gravitational force is the force by which an object attracts other objects into its center of mass. Earth attracts every objects into its center. That why we are all standing on the ground.
The weight we experience on earth is due to the gravity. That is the product of mass and acceleration due to gravity of a planet is the weight on the planet.
The weight of astronaut in earth = 60 kg
acceleration due to gravity on earth = 9.8 m/s²
mass = 60/9.8 m/s² = 6.19 kg
Acceleration due gravity on moon = 1.6 m/s²
then weight on moon = 1.6 m/s² ×6.19 kg = 9.7 kg.
Therefore, the weight of the astronaut in moon will be 9.7 kg.
Find more on gravitational force:
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An astronaut floating at rest in space throws a wrench in one direction and subsequently recoils back with a velocity in the opposite direction. Which of the following statements is/are true?
I. The velocity of the wrench is equal and opposite to the velocity of the astronaut.
Il. The momentum of the wrench is equal and opposite to the momentum of the astronaut.
III. The impulse applied to the wrench is equal and opposite to the impulse applied to the astronaut
a) ll and ill only
b) I only II only
c) I, II, and III
d) I and Il only
Answer:
a) ll and Ill only
Explanation:
Let the mass of the wrench = m
and the mass of the astronaut = M
Initially, the velocity of the astronaut and wrench are zero.
The astronaut throws the wrench in one direction and subsequently recoils back with a velocity in the opposite direction.
Let v and V be the velocity of the wrench and the velocity of the astronaut respectively.
In space, there is no external force acting, the momentum must be conserved.
So, m(0)+M(0)=m(v)+M(V)
So, 0=mv+MV
[tex]\Rightarrow mv=-MV[/tex] ...(i)
Here, the momentum of the wrench = mv, and the momentum of the astronaut= MV. The negative sign showing that both the momentum are in opposite direction.
Therefore, the momentum of the wrench is equal and opposite to the momentum of the astronaut.
According to Newton's second law, the rate of change of momentum = applied force.
Let it take [tex]\Delta t[/tex] seconds to change the momentum.
So, for the wrench
[tex]m(v-0)/\Delta t= F_w \\\\\Rightarrow m(v-0)=F_w\Delta t \\\\\Rightarrow mv=F_w\Delta t \cdots(ii)[/tex]
Here, [tex]F_w\Delta t[/tex] is the impulse applied to the wrench.
Similarly, for the astronaut
[tex]M(-V-0)/\Delta t= F_a[/tex] [negative sign (-V) for opposite direction]
[tex]\Rightarrow M(-V-0)=F_a\Delta t \\\\\Rightarrow -MV=F_a\Delta t[/tex]
Here, [tex]F_a\Delta t[/tex] is the impulse applied to the astronaut.
So, the impulse on the astronaut.
By using equations (i) and (ii)
[tex]F_a\Delta t=F_w\Delta t[/tex]
Therefore, the impulse applied to the wrench is equal and opposite to the impulse applied to the astronaut.
Hence, option (a) is correct.
a machine
of efficiency of 70% is used to raise
a body of
mass 80 kg through
a vertical distance of 3m in
40 seconds. Calculate the power input. (Take g = 10 m/s²)
Answer:
Power_input = 85.71 [W]
Explanation:
To be able to solve this problem we must first find the work done. Work is defined as the product of force by distance.
[tex]W = F*d[/tex]
where:
W = work [J] (units of Joules)
F = force [N] (units of Newton)
d = distance [m]
We need to bear in mind that the force can be calculated by multiplying the mass by the gravity acceleration.
Now replacing:
[tex]W = (80*10)*3\\W = 2400 [J][/tex]
Power is defined as the work done over a certain time. In this way by means of the following formula, we can calculate the required power.
[tex]P=\frac{W}{t}[/tex]
where:
P = power [W] (units of watts)
W = work [J]
t = time = 40 [s]
[tex]P = 2400/40\\P = 60 [W][/tex]
The calculated power is the required power. Now as we have the efficiency of the machine, we can calculate the power that is introduced, to be able to do that work.
[tex]Effic=0.7\\Effic=P_{required}/P_{introduced}\\P_{introduced}=60/0.7\\P_{introduced}=85.71[W][/tex]
what is the difference between alcoholic and Mercury thermometer based on their function?
Which of the following is an opinion about friction?
It always acts in the opposite direction as the motion of the object.
It stops objects on Earth from staying in motion forever.
It slows objects down too much.
It happens any time two objects are in contact.
Help me out please-
You'll get 40 points
My opinion about friction is that It always acts in the opposite direction as the motion of the object.
What is friction?Friction refers to the resistance of motion of one object that is moving relative to another object. Fricton has many application but it has also many disadvantages.
So we can conclude that friction is always acts in the opposite direction as the motion of the object.
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name three characteristics of sound
The rate of change of velocity or speed is known as acceleration. If a car increases it speed form 10 to 20m/s in 2 seconds, then what is its rate of change in velocity?
A) 5 m/s/s
B) 10 m/s/s
C) 20 m/s/s
D) 40 m/s/s
Answer:
A) 5 m/s/s
Explanation:
Given the following data;
Initial velocity = 10m/s²
Final velocity = 20m/s²
Time, t = 2 seconds.
In physics, acceleration can be defined as the rate of change of the velocity of an object with respect to time.
This simply means that, acceleration is given by the subtraction of initial velocity from the final velocity all over time.
Hence, if we subtract the initial velocity from the final velocity and divide that by the time, we can calculate an object’s acceleration.
Mathematically, acceleration is given by the equation;
[tex]Acceleration, a = \frac{final \; velocity - initial \; velocity}{time}[/tex]
Substituting into the equation, we have;
[tex]Acceleration, a = \frac{20 - 10}{2}[/tex]
[tex]Acceleration, a = \frac{10}{2}[/tex]
Acceleration, a = 5m/s²
A ball of mass 4kg moving with a velocity of 20m/s collides with another ball of mass 15kg moving with a velocity of 15m/s in the same direction. Calculate the velocity of the 5kg ball if the collision is perfectly inelastic.
Answer:
velocity = 16.05 m/s
Explanation:
inelastic collision formula:
m1u1 + m2u2 = (m1 + m2)v
m1 = 4kg
u1 = 20m/s
m2 = 15kg
u2 = 15m/s
find v ?
m1u1 + m2u2 = (m1 + m2)v
(4×20) + (15×15) = (4+15)v
80 + 225 = 19v
305 = 19v
19v = 305
v = 305/19
v = 16.05 m/s