Answer:
(i) The speed of the whistle is 16.[tex]\overline 3[/tex] m/s
(ii) The lowest note heard by the person is 3,818.[tex]\overline{18}[/tex] Hz
(iii) The time taken for the whistle to make one revolution is approximately 0.38468 seconds
(iv) The time interval between the person hearing the highest and lowest note is approximately 0.19234 seconds
Explanation:
The question relates to the Doppler effect for which the change in frequency is given as follows;
[tex]f_L = \left ( \dfrac{v \pm v_L }{v \pm v_S} \right ) \cdot f_S[/tex]
Where;
[tex]f_L[/tex] = The frequency heard by the listener
v = The speed of sound in air = 343 m/s
[tex]v_L[/tex] = The listener's speed
[tex]v_S[/tex] = The source's (whistle) speed
[tex]f_S[/tex] = The frequency of the source
The given parameters are;
The frequency of the whistle (source), [tex]f_S[/tex] = 4 kHz = 4,000 Hz
The radius of the horizontal circle around which the whistle is whirled = 1 m
The highest note heard by a person a large distance away = 4200 Hz
The distant listener is taken as stationary, [tex]v_L[/tex] = 0 m/s
We therefore have;
[tex]f_L = \left ( \dfrac{v \pm 0 }{v \pm v_S} \right ) \cdot f_S = \left ( \dfrac{v }{v \pm v_S} \right ) \cdot f_S[/tex]
(i) When the whistle's motion while it is being whirled towards the listener, [tex]v_S[/tex] is negative
When the whistle's motion while it is being whirled is away from listener, [tex]v_S[/tex] is positive
The highest note, [tex]f_{LH}[/tex], is obtained with the lowest denominator, that is when the source moves towards the listener and [tex]v_S[/tex] is negative, we get;
[tex]f_{LH} = 4,200 \ Hz = \left ( \dfrac{343 \ m/s }{343 \ m/s - v_S} \right ) \times 4,000 \ Hz[/tex]
[tex]\dfrac{4,200 \ Hz}{4,000 \ Hz} = \dfrac{21}{20} = \dfrac{343 \ m/s}{343 \ m/s - v_S}[/tex]
21·(343 m/s - [tex]v_S[/tex]) = 20×343 m/s
21 × [tex]v_S[/tex] = 21 × 343 m/s - 20 × 343 m/s = 343 m/s
[tex]v_S[/tex] = (343 m/s)/21 = 49/3 m/s = 16.[tex]\overline 3[/tex] m/s
The speed of the source = The speed of the whistle
∴ The speed of the source = [tex]v_S[/tex] = 16.[tex]\overline 3[/tex] m/s = The speed of the whistle
(ii) The lowest note heard by the person occurs when the denominator of the formula for the change in frequency is smallest for which we have the value of [tex]v_S[/tex] as positive and the source moves away from the observer which is presented as follows;
[tex]f_{LH} = \left ( \dfrac{343 \ m/s }{343 \ m/s +16.\overline 3 \ m/s } \right ) \times 4,000 \ Hz = 3,818.\overline {18} \ Hz[/tex]
The lowest note heard by the person = 3,818.[tex]\overline{18}[/tex] Hz
(iii) The angular velocity of the whistle, ω is given as follows;
[tex]\omega = \dfrac{\theta}{t} = \dfrac{v_S}{r} = \dfrac{16. \overline 3 \ m/s}{1 \ m} = 16. \overline 3 \ radians/second[/tex]
The angle rotated in one revolution, is 2·π radians, therefore, when θ = 2·π radians, the time, [tex]t_c[/tex], to complete one revolution is given as follows;
[tex]t_c = \dfrac{\theta}{\omega} = \dfrac{2 \times \pi \ radians}{16. \overline 3 \ radians/second} \approx 0.385 \ seconds[/tex]
Therefore, the time to complete one revolution ≈ 0.38468 seconds
(iv) The time interval between the person hearing the highest and lowest note is the time to complete half a cycle ≈ 0.38468/2 seconds ≈ 0.19234 seconds.
pls guys what is the law of electrostatic
Answer:
hello
Explanation:
The magnitude of the electrostatic force of attraction or repulsion between two point charges is directly proportional to the product of the magnitudes of charges and inversely proportional to the square of the distance between them
Write the equations of motions
Answer:
In physics, equations of motion are equations that describe the behavior of a physical system in terms of its motion as a function of time.[1] More specifically, the equations of motion describe the behaviour of a physical system as a set of mathematical functions in terms of dynamic variables. These variables are usually spatial coordinates and time, but may include momentum components. The most general choice are generalized coordinates which can be any convenient variables characteristic of the physical system.[2] The functions are defined in a Euclidean space in classical mechanics, but are replaced by curved spaces in relativity. If the dynamics of a system is known, the equations are the solutions for the differential equations describing the motion of the dynamics.
When acceleration is constant and motion is a straight line. The three equations of motion r
The unit for acceleration is always
Explanation:
Because acceleration is velocity in m/s divided by time in s, the SI units for acceleration are m/s2, meters per second squared or meters per second per second, which literally means by how many meters per second the velocity changes every second. ... The quicker you turn, the greater the acceleration.
What is the difference between catastrophism and uniformitarianism
Explanation:
Catastrophism is a geological concept or ideology that was formerly in place. It suggests that the earth crust has evolved through only drastic and violent geological events.
Uniformitarianism suggests that the earth carefully evolved over a period of time and that the processes that are occurring today have occurred in times past.
Catastrophism presents a drastic and rapid evolution of the crust. Uniformitarianism takes a gradual approach to events and suggests that we can use the present to unravel the past.A car driving at 20 m/s accelerates continuously 2m/s2 for 3 seconds. What is its final velocity
Answer: V= u+ at
V= final velocity
u=initial velocity
a=acceleration
t=time taken
V= 20 + 2*3
V= 26m/s
Explanation:
a ball rolls from x 10m to x -25m in 2.5 seconds. What was its average velocity?
Answer:
2.5=10xm is the correct one
Explanation:
Answer:
-14
Explanation:
List three ways light can be grouped based on how much light shines through or passes through them
Answer:
Materials can be classified based on the amount of light they transmit. Materials, which allow complete transmission of light, are called transparent. Any object can be seen through a transparent material. One example of transparent material is pure glass.
Explanation:
Does this help ?
Answer:
light, materials, and shadows
Explanation:
hope this helps have a good rest of your day :) sorry if incorrect
Select the correct answer.
Five locations are marked on the world map. Which location is most prone to hurricanes?
Answer: A
Explanation:
Location A represents the Caribbean region which is known for tourist attractions such as nice beaches. It is also known however, for devastating hurricanes.
Apart from mostly being islands, which puts them at risk of being in Hurricane paths, the Caribbean is warm and the air is moist. Hurricanes derive energy from these two things which is why Hurricanes attack the Caribbean rather frequently.
Answer:
Based off the picture the guy above showed me, the correct answer would be A
However, if you have a different map, choose the choice nearest to a body of water.
Hi I need help with this question (see image ).
Explanation:
a) Fixed points are the temperatures at which a thermometer is calibrated. They can refer either to the actual temperatures used for calibration, or the thermometer readings at those temperatures.
__
b) Fundamental interval is the difference between the fixed points. As with fixed points, it can refer either to the difference in actual temperature, or the difference in the corresponding thermometer readings.
Regardless of the method used to develop a scientific explanation, what does a scientist always look for?
1Trends or patterns
2proof of hypothesis
3a mathematical equation
4something never seen before
Answer:
2proof of hypothesis
Explanation:
A scientist is always on the look out for the proof of a hypothesis so as to validate their claim.
A hypothesis presented by a scientist is a testable idea. When the hypothesis is subject to a test, results are produced in form of data. The data is then analyzed to give the meaning which is the conclusion drawn So, the goal of a scientist is to find proof of their claim. The proof can come in many different forms or formatswhat types of forces can move an object?
Getting and using energy, reproducing, and maintaining structure are _______ of life.
Which number would be 16,000 when rounded to the nearest thousand? *
15,472
15,518
16,511
16,739
A 225kg race horse runs around the track with an acceleration or 13m/s2. What is the force needed by the horse?
Explanation:
The force acting on an object given it's mass and acceleration can be found by using the formula
force = mass × acceleration
From the question we have
force = 225 × 13
We have the final answer as
2925 NHope this helps you
Rahul runs a distance of 12
km with an average speed of 4.5 km/h and
Rita runs 1.6 km within 15 minutes. Who
runs faster?
Answer:
Rita runs faster
Explanation:
To obtain the answer to the question given, we determine the speed of Rita. This can be obtained as follow:
Distance = 1.6 km
Time = 15 mins
Speed =?
Next, we shall convert 15 mins to hour. This can be obtained as follow:
60 mins = 1 h
Therefore,
15 mins = 15 mins × 1 h / 60 mins
15 mins = 0.25 h
Thus, 15 mins is equivalent to 0.25 h.
Finally, we shall determine speed of Rita as follow:
Distance = 1.6 km
Time = 0.25 h
Speed =?
Speed = distance / time
Speed = 1.6 / 0.25
Speed = 6.4 Km/h
Thus Rita's speed is 6.4 Km/h
Comparing the speed of Rahul and Rita
Rahul's speed = 4.5 km/h
Rita's speed = 6.4 Km/h
We can see that Rita's speed is greater than Rahul's speed. This simply indicates that Rita runs faster than Rahul.
Which object has more momentum?
1. Caterpillar resting on a leaf?
2. Sleeping bear?
3. Llarge butterfly in flight, flying through the air?
4. Ant walking in line?
Answer:
3. Large butterfly in flight, flying through the air?
Explanation:
Momentum is simply defined as the quantity of motion a body possess. It is mathematically given as;
Momentum = mass x velocity
The larger the mass, the larger the momentum and also the velocity
Since the large butterfly is in flight, it has the largest velocity.
A sleeping bear and resting caterpillar have no momentum because their velocity is 0
A resting state through the winter.
Adaptation: Bear sleeping in a cave during the winter months
0 A. Locomotion
B. Hibernation
C. Migration
D. Defense
Answer:
b
Explanation:
Bears hibernate in the winter
***URGENT****calculate the work done by a crane lifting a 3.8mg ( megagrams or tonnes) load to a height of 23m. ( g= 10 m/s squared)
Thank you, :))
Answer:
874000J
Explanation:
Given parameters:
Mass = 3.8Mg = 3.8 x 10⁶g
To kilograms;
1000g = 1kg
3.8 x 10⁶g will be 3.8 x 10³kg
height = 23m
Unknown :
Work done = ?
Solution:
The work done by a body is give as;
Work done = mgh
m is the mass
g is the acceleration due to gravity
h is the height
Now insert the parameters and solve;
Work done = 3.8 x 10³ x 10 x 23 = 874000J
. If an object travels at a constant velocity, how does its average velocity compare to its
instantaneous
velocity throughout the trip?
Answer:
The average velocity is equal to the instantaneous velocity
Explanation:
The average velocity, [tex]\overline v[/tex], is given as follows;
[tex]\overline v = \dfrac{\Delta y}{\Delta t}[/tex]
Where;
Δy = The change in displacement
Δt = The change in time
The instantaneous velocity is the derivative found of the position of the object's displacement with respect to time
Therefore, the instantaneous velocity, [tex]v_{inst}[/tex] = The limit of the average velocity as the change in time becomes closer to zero
[tex]v_{inst} = \lim_{t \to 0} \left (\dfrac{\Delta y}{\Delta t} \right ) = \dfrac{dy}{dx}[/tex]
When the velocity is constant, the displacement time graph is a straight line graph, and the slope of the displacement-time graph which is the same as the velocity is constant and therefore, we have;
[tex]Slope \ of \ straight \ line \ graph = \dfrac{y_2 - y_1}{t_2 - t_1} = \dfrac{\Delta y}{\Delta t}= \dfrac{dy}{dx}[/tex]
Therefore, for constant velocity, we have, [tex]\overline v[/tex] = [tex]v_{inst}[/tex] the average velocity is equal to the instantaneous velocity.
Which property of a substance indicates wheaten the substance is a liquid or a solid at room temperature
Answer:
physical property
Explanation: Some substances exist as gases at room temperature (oxygen and carbon dioxide), while others, like water and mercury metal, exist as liquids.
What occurs when air moves from an area of high pressure to an area of lower pressure
Please please help me. I will mark you as brainliest if you’re right !
1. What happens to the period of a pendulum and the period of a spring as the
amplitude of the oscillation increases? Briefly give an explanation for this
relationship. (5 points)
Answer:
The Pendulum falls but the longer the period or the back and forth swing the greater amplitude the oscillation depends on the amplitude
Explanation:
What are combined vectors that go in one direction?
A. equal in magnitude
B. one-dimensional
C. two-dimensional
D. displacements
Answer:
One-dimensional
Explanation:
what planet are people working on so they can move there
Answer:
mars
Explanation:
just search it up
Answer:
Mars I belive
Explanation:
You are freezing juice to make your own popsicles. Describe what happens on a molecular level as the juice freezes. Be sure to us e appropriate science vocabulary in your response.
Answer:
When water freezes to form ice, the molecules would be vibrating in place rather than moving round. It is a result of a decrease in the kinetic energy of the molecules of water. It is said that the temperature and the kinetic energy of the molecules is directly proportional which means that when temperature is increased, the kinetic energy of the molecules would increase as well making the molecules move around. However for this case, when we day the system is cooled then it means the temperature is decreased which would result to the decrease of the kinetic energy of the molecules.
what is warmer 0 f or 0 c
Astrology is considered a science because it is grounded in scientific research. Please select the best answer from the choices provided T
Answer:
False. Astrology is not a science.
Explanation:
Astrology is a collective term for ideas about the supposed connection between the fate of people and events on Earth and the position of the celestial bodies. It mainly concerns the places in the sky of the sun, moon and planets, which were referred to as stars in ancient times, usually against the background of the fixed stars in the Zodiac. Although astrology cannot be confirmed despite research, and scientists have long rejected the principles of astrology as pseudoscience, many people continue to practice and / or believe in it.
Answer:
False
Explanation: i got it right in edge
Rose got out of bed and walked from her room to the bathroom 10 m/s in 2s. She was traveling southeast. What was her acceleration?
Answer:
Acceleration = 5m/s² Southeast
Explanation:
Given the following data;
Final velocity = 10 m/s
Time = 2secs
To find acceleration;
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]
[tex]a = \frac{v - u}{t}[/tex]
Where,
a is acceleration measured in [tex]ms^{-2}[/tex]
v and u is final and initial velocity respectively, measured in [tex]ms^{-1}[/tex]
t is time measured in seconds.
We know that Initial velocity = 0m/s
Substituting into the equation, we have;
[tex]a = \frac{10 - 0}{2}[/tex]
[tex]a = \frac{10}{2}[/tex]
Acceleration = 5m/s² Southeast.
HELP!! I’m DESPERATE!! 19 POINTS!!!
Which action might lead scientists to develop new explanations about the
universe?
A. Becoming familiar with the history of space exploration
O B. Speculating on whether conditions on other planets might support
life
O C. Developing new technologies designed to see farther into space
than before
D. Wondering about the present size and shape of the universe and
how it formed
c. Developing new technologies designed to see farther into space
than before
What is universe?The universe is everything including all of space, and all the matter and energy that space contains. Also it includes time itself and, of course, it includes us.
What began as a sequence one-upmanship in space-related technological advancements between the U.S. and the Soviet Union would spawn incredible progress observed in innovation to this day. The battle for dominance not only as a global superpower, but a space power, led the United States and the Soviet Union to race to put men in space and eventually on the moon.
The launch of the Soviet satellite Sputnik on Oct. 4, 1957, would place pressure on the U.S. to design technologies crafted for space exploration. This, in turn, spurred a series of innovations in technology that would have far reaching impacts beyond space.
These technologies can be seen as developments in modern healthcare, construction, and transportation. Relevant examples include medical imaging techniques, artificial limbs, water filtration systems, solar panels, firefighting equipment, shock absorbers, air purifiers, home insulation, weather resistant airplanes, infrared thermometers, and countless other vital inventions.
While all these creations help sustain essential aspects of modern life, we carry one of the largest technological advancements from the space race in our pockets today.
Therefore, Developing new technologies designed to see farther into space than before lead scientists to develop new explanations about the universe.
Learn more about universe here:https://brainly.com/question/15844073
#SPJ1
If mass and velocity are unknown when using de Broglie's wavelength formula, what alternative value must we have to successfully determine the wavelength
Answer:
The particle momentum, p
Explanation:
A particle's de Broglie's wavelength is an indication of the scale in length where the particle's wave-like properties are important. The symbol of de Broglie wavelength is λ or [tex]\lambda _{dB}[/tex] given as follows;
The de Broglie's wavelength formula is given as follows;
[tex]\lambda = \dfrac{h}{m \cdot v} = \dfrac{h}{p}[/tex]
Where;
λ = The wavelength of the particle in meters
v = The velocity of the particle in meters/seconds
m = The mass of the particle in kilograms
p = The momentum of the particle
h = Planck's constant = 6.626 × 10⁻³⁴ J/Hz
Therefore, the alternative value that we must have to successfully determine the wavelength if the mass and velocity are unknown, is the momentum, p of the particle.