A police siren has a frequency of 340.0 Hz when the car is stationary and the temperature is 20°C. The police car at point S moves to the right with a speed of 22.0 m/s.
a. What frequency does observer A hear?
b. What frequency does observer B hear?
c. Suppose observer A is moving toward the stationary police car. What is the speed of observer A if the frequency heard is 369 Hz?
Answer:
a) 361.7 Hz
b) 318.1 Hz
c) 29.3 m/s
Explanation:
a) Speed of sound in 20 degrees celcius is 343 m/s.
Use v=wavelength*frequency to find wavelength.
343=wavelength*340
wavelegth=1.009 meters
Relative speed of waves to observer A = 343+22 = 365 m/s
Plug it back in.
365=1.009*F
F=361.7 Hz
b) Relative speed of waves to observer B = 343-22 = 321 m/s
Plug it back in.
321=1.009*F
F=318.1 Hz
c) STATIONARY CAR, so 369Hz=v/1.009. v=372.3, 372.3-343=29.3m/s!
Why do some organisms never turn into fossils?
A. They are far too large to be buried in the ground.
B. They are made mostly of soft tissues.
C. They contain too much protein to be preserved.
D. They contain chemicals that prevent the hardening of their bodies.
Answer:
The answer is B.
Explanation:
Since they are made up of soft tissues, they decompose become they become fossils.
Question 4 (1 point)
A golf ball is suspended by a cord held in a golfers hand. The reaction to the force of
gravity on the golf ball is the force exerted by
Answer:
The force of the golf ball on Earth!
Explanation:
Action/Reaction Pairs work like this:
Earth on Golfball, Golfball on Earth.
What is the current if a charge of 25 coulombs passes in 5 seconds?
Answer: 5 amps
Explanation: I = Q/t
What is the study of economics?
Answer:
Economics is the study of how societies use scarce resources to produce valuable commodities and distribute them among different people.
Explanation:
The ultimate goal of economic science is to improve the living conditions of people in their everyday lives.
Hope this helps!
Answer:
the branch of knowledge concerned with the production, consumption, and transfer of wealth. (basically the study of money and not just banks but how it effects the world)
Explanation:
that is a difference between a law and a hypothesis?
A law describes how two variables affect each other, but a hypothesis only discusses one variable.
A law must be testable so that it can be proven, but a hypothesis is an untestable explanation.
A hypothesis includes an explanation for why two variables affect each other, but a law only describes how they
affect each other
A hypothesis may or may not be testable, but a law is an untestable explanation of why two variables affect each
other and cannot be proven
Answer:
A hypothesis is a limited explanation of a phenomenon; a scientific theory is an in-depth explanation of the observed phenomenon.
A law is a statement about an observed phenomenon or a unifying concept, according to Kennesaw State University. ... However, Newton's law doesn't explain what gravity is, or how it works.
Please help me like rn it’s an embergency
Answer:
first one
Explanation:
electromagnetism is the forces and fields associated with charge
Calculate the efficiency of a hairdryer that has a total power input of 2000W and a useful power output of 1200W.
Consider an alien on a planet with an acceleration of gravity equal to 20 m/sec^2. If the alien's mass is 10 kg, how much does the alien weigh?
Answer:
the weight of alien is 200 newtons
Explanation:
The computation of the alien weight is shown below:
Given that
Acceleration = 20m/sec^2
And, the mass is 10 kg
So, the weight of alien is
= 20 × 10
= 200 newtons
hence, the weight of alien is 200 newtons
Explain
8. How do you know that
the bicyclists in the first
panel above are moving
at a constant velocity?
Answer:
Constant velocity means that the object in motion is moving in a straight line at a constant speed. You know this as in the first panel each arrow representing each second is the same width apart, therefore you know the cyclists are moving at a constant velocity. Compare this to the second box representing changing speed. The arrows are different lengths meaning each second the cyclists are moving at a different speed and are not moving at a constant velocity.
Hope this helped.
aight here's the question:
Homeboy Joe is running at 6.65 m/s while Homegirl Jill is running at -1.10 m/s. Home boy Joe and Homegirl Jill hit each other. Homeboy Joe not wanting to be a stage 5 clinger. he makes sure he doesn't hold onto Homegirl Jill after they collide. If Homeboy Joe's mass is 99.5 kg and Homegirl Jill's mass is 68.8 kg. what is Homegir Jill's velocity after they hit if Homeboy Joe's velocity is 2.35?
***Round to the nearest hundredth***
Correct Answer: 5.12
I can't do PEMDAS to save my life can someone show me the correct way to solve with work?
Answer:
[tex]5.12\:\text{m/s}[/tex]
Explanation:
From the conservation of momentum, the total momentum of the system before and after the collision must be the same. Therefore, let the momentum of Homeboy Joe be [tex]p_b[/tex] and let the mass of Homegirl Jill be [tex]p_j[/tex]. We can write the following equation:
[tex]p_{bi}+p_{ji}=p_{bf}+p_{jf}[/tex], where subscripts [tex]i[/tex] and [tex]f[/tex] represent initial and final momentum respectively.
The momentum of an object is given by [tex]p=mv[/tex].
Therefore, we have:
[tex]m_{b}v_{bi}+m_{j}v_{ji}=m_{b}v_{bf}+m_{b}v_{jf}[/tex] (some messy subscripts but refer to the values being plugged in you're confused what corresponds with what).
Plugging in values, we have:
[tex]99.5\cdot 6.65 + 68.8\cdot (-1.10)=99.5\cdot 2.35+ 68.8\cdot v_{jf}[/tex].
Solving, we get:
[tex]v_{jf}=\frac{99.5\cdot 6.65+68.8\cdot (-1.10)-99.5\cdot2.35}{68.8},\\v_{jf}=5.11875,\\v_{jf}\approx \boxed{5.12\:\text{m/s}}[/tex].
It's important to note that velocity is vector quantity, so the negative velocity assigned to Jill simply implies she is moving at [tex]1.10\:\text{m/s}[/tex] in the opposite of Joe's direction. After the collision, she is now moving [tex]5.12\:\text{m/s}[/tex] in the same direction that Joe was initially moving, due to Joe's relatively large mass and initial velocity.
I need help please so fast
Answer:
DUumb
Explanation:
Duumb
hii pls help i’ll give brainliest if you give a correct answer
Answer: the first option: "the period of revolution of the Moon around Earth"
Answer:
The answer your looking for would be D.
Explanation: The other answers don't make any sense you can cancel them out D is the the answer the period of rotation of the moon around its axis.
What type of tool would best be used to map a section of the ocean floor?
Echo sounding is the key method scientists use to map,uses sound waves bounced off the ocean bottom.
what's the difference between work and power
Work is defined as the process of energy transfer to the motion of an object through the application of force. ... Power is defined as the amount of energy transferred in unit time. The SI unit of power is the watt.
You need to have power or energy, to be able to work. When you reach another lesson, you will learn about time, which is the flow of work you have done. You need more work than time for your work to count.
If you need more help, don't hesitate to ask!
May I please have brainliest?
WORK is the amount of energy used to get something done.
POWER is the RATE at which the energy is used and the work is done.
A car traveling at 5m/s starts to speed up after 3 seconds its velocity has increased to 11 m/s what is its acceleration
Answer:
a=(v-u)/t
Explanation:
a =(11-5)/3
a= 8/3
a= 2.6 m/s
The acceleration of the car is 2 m/s².
What is acceleration?Acceleration is the rate at which speed and direction of velocity vary over time. A point or object going straight ahead is accelerated when it accelerates or decelerates.
Even if the speed is constant, motion on a circle accelerates because the direction is always shifting. Both effects contribute to the acceleration for all other motions.
Acceleration is a vector quantity with and SI unit of it is meter/second².
Given parameters:
Initial speed of the car: u = 5 m/s.
Final speed of the car: v = 11 m/s.
Time interval: t = 3 second.
Change is speed = final speed - initial speed
= 11 m/s - 5 m/s
= 6 m/s.
Hence, its acceleration is = change in speed / time interval
= 6/3 m/s²
= 2 m/s².
Learn more about acceleration here:
https://brainly.com/question/12550364
#SPJ2
A sled starts off with an initial velocity of 8 m/s and slows down to 2 m/s after 3 seconds. What was its acceleration?
Answer:
-2m/s
Explanation:
As your scooter coasts downhill, your speed goes from 4 m/s to 6 m/s in 1.5
seconds. What is your acceleration?
A. 2.4 m/s
B. 1.3 m/s
C. 0.8 m/s
D. 3.0 m/s
Answer:
it is B.
Explanation:
A box has a mass of 6.0 kg. What is its weight on the mars, where the acceleration due to
gravity is 0.38 times that on Earth? *
Answer:
The weight of the box is 22.38 N.
Explanation:
The weight (W) of the mass is given by:
[tex] W = mg [/tex]
Where:
m: is the mass of the box = 6.0 kg
[tex]g_{m}[/tex]: is the acceleration due to gravity of mars
Since the acceleration due to the gravity of mars is 0.38 times that on Earth we have:
[tex]g_{m} = 0.38g_{E} = 0.38*9.81 m/s^{2} = 3.73 m/s^{2} [/tex]
Hence, the weight of the mass is:
[tex] W = mg = 6.0 kg*3.73 m/s^{2} = 22.38 N [/tex]
Therefore, the weight of the box is 22.38 N.
I hope it helps you!
How much work is required to raise a 0.75 kg flag from shoulder height (1.2m) To the top of the flag pole (4 m)?
Answer:
20.58J
Explanation:
[tex]W=\Delta E[/tex]
[tex]\Delta E= \Delta U_{g}[/tex]
[tex]\Delta U_{g}=mgh[/tex]
[tex]mgh=(.75kg)(9.8m/s^2)(2.8m)=20.58J[/tex]
Does anyone understand This question if you do can you tell me the answer
Answer:
50N increasing
Explanation:
it looks like we want the net force. this is the sum of all forces acting on the object. here the problem is extremely simplified and we are even given the values of force. this looks like the rocket is producing an upward force of 160 newtons. it also looks like maybe weight (gravity) and drag (air resistance) are producing downward force against the rocket. we can say those would be subtracting from the amount of upwards force. so 160-40-70=50N. since the force is positive that means we will still have a magnitude of force vector that points upward and so we will increase.
Two dogs are pulling on a chew toy. One dog pulls the chew toy with 64 N (E) and
the other pulls the chew toy with 31 N [W]. Determine the NET FORCE acting on
the chew toy.
Answer:
33 N
Explanation:
Given that,
One dog pulls the chew toy with 64 N (E) and the other pulls the chew toy with 31 N [W].
We need to find the net force acting on the chew toy. Let East be taken positive and west be taken negative. So,
[tex]F_{net}=+64+(-31)\\\\=33\ N[/tex]
So, the net force acting on the chew toy is equal to 33 N.
Which location, 23 degrees or 48 degrees would experience the same earthquake at stronger intensity?Explain why.
Answer:
48 degress
Explanation:
An earthquake causes many different intensities of shaking in the area of the epicenter where it occurs. So the intensity of an earthquake will vary depending on where you are. Sometimes earthquakes are referred to by the maximum intensity they produce. In the United States, we use the Modified Mercalli Scale. Earthquake intensity is a ranking based on the observed effects of an earthquake in each particular place. Therefore, each earthquake produces a range of intensity values, ranging from highest in the epicenter area to zero at a distance from the epicenter.
PLS ANSWER FAST WILL GIVE BRAINLY!!!
When you bounce a ball eventually it will stop bouncing. Where does the energy go?
Answer:
Into sound and heat energy due to friction.
PLEASE ANSWER QUICK :) -
As a geologist, you come across a landscape with a massive fault zone that
produces a lot of large earthquakes but has no volcanoes. What type of plate
boundary is this? What are the movements of plates there? Where is this type
of boundary found in California?
Answer:
At a convergent boundary where both plates are continental, mountain ranges grow and earthquakes are common. At a transform boundary, there is a transform fault and massive earthquakes occur but there are no volcanoes. Processes acting over long periods of time create Earth's geographic features.
Explanation:
What happens to the force between charged and uncharged objects as the distance between them decreases?
Answer:Thus, if each of the charges were reduced by one-half, the repulsion would be reduced to one-quarter of its former value. Also In electrostatics, the electrical force between two charged objects is inversely related to the distance of separation between the two objects. ... And decreasing the separation distance between objects increases the force of attraction or repulsion between the objects.
Hope this helps have a awesome night/day❤️✨
Explanation:
Nothing, until those two objects physically touch each other; contact aligns polarity among the now single shared mass.
(Your question never states if both objects are unique or similar polar charges, so I just assumed they were both neutral objects existing within an electric field.)
So a better question would then be, what is gravity’s relationship with an electric field?
You could solve this with the following: confine the electric field’s volume to a set variable (never increasing nor decreasing in size or shape); density is variable and easily definable. This creates the limit to build upon. This density has to be fluid and has electron mass (full of electrons at rest mass, so with substance but no movement). Within, create a closed system (the hard part in this equation; outside interference like ambient light will eschew results) where each variable of kinetic energy then is accounted for or measurable (including heat and light, and the physical movement of the two objects)
Determine the mass for both objects, calculate gravity for both and each body’s inertia on the other as a sum over distance. record results. Polarity is shared across the masses until there is no longer inertia (one mass or contact).
Identify the order of The Sun, Moon, and Earth During a solar and lunar eclipse.
Answer:As the Earth rotates on its axis and revolves around the Sun, day and night and seasons result. When the new moon comes between the Earth and the Sun along the ecliptic, a solar eclipse is produced. When the Earth comes between the full moon and the Sun along the ecliptic, a lunar eclipse occurs.
Explanation:
Some students found this information about an energy saving lamp and a filament lamp that give out almost the same amount of light.
Describe the advantages and disadvantages of each type of lamp.
Answer:
By replacing your home's five most frequently used light fixtures or bulbs with models that have earned the ENERGY STAR, you can save $75 each year.
Compared to traditional incandescents, energy-efficient lightbulbs such as halogen incandescents, compact fluorescent lamps (CFLs), and light emitting diodes (LEDs) have the following advantages:
Typically use about 25%-80% less energy than traditional incandescents, saving you money
Can last 3-25 times longer.
A woman hikes 2.5 kilometers in 30 minutes, and then 3 kilometers in 20 minutes, and finally 2 kilometers in 10 minutes. What was her average speed?
Answer:
7.5 kph
Explanation:
2.5+3+2=7.5
In your own words explain why the thickness and length of a wire could effect the flow of electrons
Answer:
(you can use my exact words) The length and thickness would make it so that the electrons move differently than they would a shorter and thinner wire because with the wire being longer the electrons would have a longer trip and with the wire being thicker the electrons would be more spread out and move be able to move more freely