The Doppler effect is the change of pitch heard when the source of the sound approaches and then moves away from a stationary person. So, the correct option is A.
What is Doppler effect?The Doppler effect or Doppler shift is defined as the phenomenon observed when a source of waves is moving with respect to an observer. For example, an ambulance passing us with the sound of its siren is a common physiological demonstration of the Doppler effect.
The frequency increases when the listener and the source are approaching each other, while the frequency decreases when the listener and the source are moving away from each other. The Doppler effect is the change of pitch heard when the source of the sound approaches and then moves away from a stationary person.
Therefore, the correct option is A.
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Which of the following is BOTH an isotope and ion of Chlorine? plz help
a
B
c
D
Answer:
The answer is C.
Explanation:
because if you look ay the nutrons you can see that it adds to the protons
Answer:
C
Explanation:
Isotopes of Chlorine (Cl) gain an electron when they form ionic bonds. This results in a negative ion (the Chloride ion). ... When the charge on an atom is zero it means the number of protons is equal to the number of electrons. The atom is said to be neutral and there will not be a + or - written after the element symbol.
A person trapped outside during a thunderstorm should
Answer:
should stay away from trees, water, and tall objects.
Answer: the answer is
stay away from trees, water, and tall objects.:)Explanation:
Physics question......
Answer:
I think it is A or B, but more B as for John used 20 more net force. I recommend doing some research, sorry.
Answer:
I think the answer is B, I may be wrong...
Explanation:
An object, 5 cm high, is placed on the principal axis of a diverging lens of focal length 20 cm. The object is 30 cm from the lens.
Use a scaled diagram to locate the image formed by the lens.
Answer:
The answer is 70 cm
Explanation:
If you add All the numbers together, you receive an 55 cm then you add 15 because the points on the diagram also count.
The figure shows the regions of the electromagnetic spectrum. Which of these statements is true?
A. X-rays are shorter than visible light waves.
B. Ultraviolet waves are longer than radio waves.
C. Visible light waves are longer than microwaves.
D. Infrared waves are shorter than ultraviolet waves.
Answer:
A. X-rays are shorter than visible light waves.
Explanation:
The correct choice from the given options is that x-rays are shorter than visible light waves.
X - rays falls into the category of short-wave radiations because they have short wavelength
Only gamma rays are shorter than x-rays. X-rays are highly energetic in nature and they have very high frequency. So, they have very short waves. The other choices are not correct.a physical quantity is defined as mass per uint volume .what is its si unit.
2. Arrange the following types of electromagnetic waves in order by wavelength, from longest to
shortest: Gamma rays, visible light, infrared radiation, ultraviolet radiation, microwaves, radio
waves, X-rays
Answer:
Radiowaves > microwaves> Infrared radiation > visible light > Ultraviolet radiation > x -rays > gamma rays
Explanation:
To solve this problem, we use the electromagnetic spectrum as a reference. On the electromagnetic spectrum, the lesser the wavelength, the higher the frequency and more energetic a wave is.
Therefore;
Radiowaves > microwaves> Infrared radiation > visible light > Ultraviolet radiation > x -rays > gamma rays
So, radiowaves have the longest wavelength and gamma rays have the shortest.
Answer:
Radio, microwave, infrared radiation, visible light, ultraviolet radiation, x-rays and gamma rays.
Explanation:
These electromagnetic waves are arranged from longest to shortest wavelengths.
Have an amazing day!
A car of mass 1000 kg is travelling at 10 m/s. What is its kinetic energy?
Answer:
50,000
Explanation:
kinetic energy=1\2×mv^2
=1\2×1000kg×10×10
=50000
A dog starts at the origin and runs forward at 6m/s for 1.5s and then turns around to fetch the ball by running backward at 7m/s for 3s. If the dog runs back to the origin at 4m/s the how much time has elapsed between the start and when he returns with the ball
Answer:
Total time elapsed between the start and when he returns with the ball is 7.5s
Explanation:
From the question,
- The dog starts at the origin and runs forward at 6m/s for 1.5s. First, we will determine the distance covered while running forward.
From
Speed = Distance / Time
Distance = Speed × Time
Speed = 6m/s
Time = 1.5s
∴ Distance = 6m/s × 1.5s
Distance = 9m
That is, the dog covered a distance of 9m while running forward.
- The dog turns around and runs backward at 7m/s for 3s. Now, we will also determine the distance the dog covered backwards.
Distance = Speed × Time
Speed = 7m/s
Time = 3s
Distance = 7m/s × 3s
Distance = 21m
The dog's displacement from the origin is 21m - 9m = 12m
Now, to calculate how much time has elapsed between the start if the dog runs back to the origin at 4m/s, we will first determine the time the dog spent back to the origin and then add to the time spent for the first two distances.
To get back to the origin, the dog needs to cover 12m
From
Speed = Distance / Time
Time = Distance / Speed
Distance = 12m
Speed = 4m/s
∴ Time = (12m) / (4m/s)
Time = 3s
Therefore, the dog spent 3s to run back to the origin.
Hence, total time elapsed = 1.5s + 3s + 3s
Total time elapsed = 7.5s
What is a heating curve of water?
Answer:
eye
Explanation:
How much potassium nitrate (KNO3) would dissolve in 50 milliliters of water at 45ºC given that 55g of KNO3 is dissolved in 150mL of water at 45°C.
A. 19.7g
B. 15.1g
C. 18.3g
D. 23.3g
Science; 4."Energy cannot be created or destroyed". Explain what this means and give an example to explain your
reasoning.
Answer:
matter
Explanation:
A car accelerates from 10 m/s to 22 m/s in 6 seconds. What is the car’s average acceleration?
A. -2 m/s2
B. 12 m/s2
C. -12 m/s2
D. 2 m/s2
A
is to mutilpy to each other
When A car accelerates from 10 m/s to 22 m/s in 6 seconds, the average acceleration of the car is 2 m/s². Hence, option (D) is correct
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.
Initial speed of the car = 10 m/s.
Final speed of the car = 22 m/s.
Time internal = 6 seconds.
The average acceleration of the car is = change in speed/time interval
= (final speed - initial speed)/time interval
= (22 m/s - 10 m/s)/6 seconds
= 12 m/s / 6 seconds
= 2 m/s²
Hence, the average acceleration of the car is 2 m/s².
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What type of electrical cord has a ground?
3 pronged cord
2 pronged cord
Explanation:
One prong is known as the hot wire, where the electricity comes in, while the second prong is the neutral wire and electricity leaves. Recall that a circuit must be made for electrons to flow. This means that electrons enters your house through the transmission wires and then the electrons leave along the same lines they entered (just along a different wire).
This set up describes a 2 pronged cord. Adding a third prong allows for a grounding to happen. In the event of an electrical surge, when too many electrons are flowing, disaster is likely to happen without some kind of safety features. The grounding prong allows electrons to seek the ground. You can think of it like a drain in a bathtub when too much water gets in the tub.
Answer:
3 pronged cord
Explanation:
6th grade science!!!!!!!!!!
Answer:
D. All of the above
Explanation:
Global warming may cause all of the given choices.
Global warming is the rise in surface temperature. This is due to the trapping of heat within the earth surface.
It is as a result of huge amount of greenhouse gases within our atmosphere. They typically permit short wave radiations to escape and they do not allow short wave radiation to pass through. This in turn produces heat.
The heat can melt polar ices and glaciers. This in turn will cause sea levels to rise. Also, the ocean temperature will generally increase due to this.What is the gravitational force of attraction between a 55 kg boy and a 40 kg girl if they are 0.10 meters apart?
Answer:
[tex]1.5\cdot 10^{-5}\:\mathrm{N}[/tex]
Explanation:
Newton's Law of Gravitation is given as:
[tex]F=G\frac{m_1m_2}{r^2}[/tex], where [tex]G[/tex] is gravitational constant [tex]6.67\cdot 10^{-11}[/tex] and [tex]r[/tex] is the distance between their centers of mass.
Therefore, the gravitational force between them is:
[tex]F=6.67\cdot 10^{-11}\frac{55\cdot40}{0.1^2}= \fbox{$1.5\cdot 10^{-5}\:\mathrm{N}$}[/tex] (two significant figures).
Which statement about plant and animal cells is true?
A. Both have a cell wall to give them support.
B. Both have a large vacuole to store water.
C. Both use mitochondria to release energy.
D. Both use chloroplasts to store energy.
Answer:
C. Both use mitochondria to release energy
Explanation:
Plant cells have a cell wall, a large vacuole and chloroplasts but animal cells do not.
Temperature
Energy Input
The three states of matter are modeled in the heatind cu
curve seen here. Identify ALL of the changes that must take place for a
substance to change state, from a solid to a gas.
A)
Pressure increases
B)
Temperature increases
19
7
Particles spread apart
D)
Kinetic energy increases
E)
Particle motion increases
Answer:
Particles spread apart, temperatue increases, pressure increases
Explanation:
A truck slows from a velocity of 25 m/s to a stop in 70 m. What was the truck’s acceleration
v^2-u^2=2 x a x d
25^2-0^2=2 x a x 70
625-0=140 x a
625=140a
a=625/140
a=4.46 m/s^2
im not very sure but i think this is how you do this
How many Joules of energy are required to make 50 kg of ice completely melt?
Hv = 226,000 J/kg
Hf = 334,000 J/kg
Answer:
In order to answer this question, you need the enthalpy of fusion of ice, which is 333.55 J/g (Joules/gram). The enthalpy of fusion is the amount of heat that must be absorbed or lost in order to change physical state.
The number of Joules required to melt the ice = enthalpy of fusion of ice x mass of ice.
1 kg = 1000g
40kg x (1000g/1kg) = 40,000g
Joules needed to melt the ice = 333.55 J/g x 40000 g = 13342000 J or
1.3342 x 107 J
Explanation:
Instead of 40kg input 50kg and get the answer
A squirrel runs at a speed of 9.9 m, with 25 J of kinetic energy. What is the squirrel’s mass?
Answer:
The mass of the squirrel is 0.51kg
A squirrel runs at a speed of 9.9 m/s with 25 J of kinetic energy.
What is the squirrel’s mass?
Answer: 0.51 kg
If a 1.3 kg ball is dropped from the top of a 33.7 meter building what is its potential energy before it is dropped?
B) What is the maximum velocity of the ball in problem 1 just before it hits the ground?
C) How much kinetic energy does the ball in problem 1 have after it has fallen 10 m down the building?
Answer:429.338 J; 25.7 m/s; 127.4 J
Explanation:
Given
mass of ball m=1.3 kg
Height of building H=33.7 m
(a)Potential Energy before dropping [tex]=mgH=1.3\times 9.8\times 33.7=429.338\ J[/tex]
(b)Velocity Just before hitting the ground
[tex]v=\sqrt{2gH}=\sqrt{2\times 9.8\times 33.7}=25.7\ m/s[/tex]
(c)After falling 10 m
Here initial velocity is zero
using [tex]v^2-u^2=2as[/tex]
Here,
[tex]v=\text{final veloity}[/tex]
[tex]u=\text{Initial velocity}[/tex]
[tex]a=\text{acceleration due to gravity}[/tex]
[tex]s=\text{displacement}[/tex]
Putting values
[tex]v^2-0=2\times 9.8\times 10\\v=14\ m/s[/tex]
So, kinetic energy [tex]\dfrac{mv^2}{2}=\dfrac{1.3\times 196}{2}=127.4\ J[/tex]
A 2.5 kg block starts with a speed of 3 m/s, goes down a 4 m hill, and then slides up a new hill but stops when it is only 1.5 m high.
a) How much work was done by friction?
b) If there was no friction, how high could the block have slidden without stopping?
Answer:
See the answers below
Explanation:
This problem can be solved by means of the law of conservation of energy, which tells us that the energy between two points is conserved, that is, remains the same.
That is to say, we have two points, the point A where it starts to move and reaches the point B that is 1.5 [m] high, where it stops.
The key to solving this problem is to identify the types of energies at each point. At point A we have kinetic energy and potential energy where the block moves at speed 3 [m/s] at a height of 4 [m]. Whereas at Point B we only have potential energy, since the body is at a height of 1.5 [m], relative to the ground.
a)
Since between the displacement between points A and B there is a friction force, this friction force decreases the final energy in B, in this way the energy or work of the friction will have a negative sign.
[tex]E_{A}-W_{A-B}=E_{B}[/tex]
Now replacing in the above equation.
[tex](\frac{1}{2}*m*v^{2}+m*g*h_{1})-W_{1-2}=m*g*h\\(\frac{1}{2}*2.5*(3)^{2}+2.5*9.81*4)-W_{1-2}=2.5*9.81*1.5\\\\W_{1-2}=72.56[J][/tex]
b)
We must use the same equation, but this time eliminating the Working term due to friction.
[tex]E_{A}=E_{B}\\\frac{1}{2}*m*v^{2}+m*g*h_{A}=\ m*g*h_{B}[/tex]
[tex](\frac{1}{2}*2.5*(3)^{2}+2.5*9.81*4) =\ 2.5*9.81*h_{B}\\h_{B}=4.45 [m][/tex]
As we can see without friction the block can reach a higher height
At 1:00 a.m., someone breaks a window in the back of a store and robs the safe. On the way out, the thief is cut on a piece of broken glass. A forensic team collects and tests a sample of blood left behind by the thief. It is O–. The police bring in a suspect with a cut forearm who was arrested just three blocks from the store. The person resembles someone seen leaving the store at the time of the robbery. A sample of the suspect’s blood is taken and tested for blood type. Once the suspect’s blood is mixed with anti-A serum, it is immediately clear that the suspect is not the person who was cut on the broken glass in the store. How did the test indicate that fact?
Answer:dd
Explanation:
A 0.016-kg piece of iron absorbs 1086.75 joules of heat energy, and its temperature changes from 25°C to 175°C. Calculate the specific heat capacity of iron. Equation : c = Q/mt * 2608.2 J/(Kg*°C) 3477.6 J/(Kg*°C) 452.8 J/(Kg*°C) 8.7 J/(Kg*°C)
Answer:
452.8125J/Kg°C
Explanation:
The quantity of eat absorbed by the iron is expressed as;
Q = mc∆t
Q = 1086.75 joules
m is the mass= 0.016kg
c is the specific heat capacity
∆t is the change in temperature = 175-25 = 150°C
Get c;
From the formula;
c = Q/m∆t
c = 1086.75/0.016(150)
c =1086.75/2.4
c = 452.8125J/Kg°C
Hence the specific heat capacity of iron is 452.8125J/Kg°C
which statement best describes the impact of space program on Florida
Answer:
B
Explanation:
did the test and i dont know the answer lol good luck bud gg
Which change of state takes place when a gas loses energy?
A. condensation
B. evaporation
C. molting
D. solidification
Answer:
Condensation (((((((((((((
An object is moving in a straight line at a constant speed. A resultant force begins to act upon the object. State the ways in which the force may change the motion of the object
Answer:
accelerate / increase speed OR decelerate / decrease speed OR stop B1
change direction / move in a curve o.w.t.t.e
Explanation:
accelerate / increase speed OR decelerate / decrease speed OR stop B1
change direction / move in a curve o.w.t.t.e
A combination of the skill-related fitness components can determine one's
Please select the best answer from the choices provided.
True or false
A flight attendant pulls her 70 N flight bag a distance of 318 m along a level airport floor at a constant velocity. The force she exerts is 41 N at an angle of 57° above the horizontal.
Complete question :
A flight attendant pulls her 70 N flight bag a distance of 318 m along a level airport floor at a constant velocity. The force she exerts is 41 N at an angle of 57° above the horizontal.
(a) Find the work she does on the flight bag.
(b) Find the work done by the force of friction on the flight bag.
(c) Find the coefficient of kinetic friction between the flight bag and the floor.
Answer:
7107 J ; - 7107 J ; 0.55
Explanation:
Given that :
Distance, d = 318m
Applied force = 41 N
θ = 57°
A.) Workdone = Force exerted along direction of motion
Workdone = applied Force * distance * cosθ
Workdone = 41 * 318 * cos57 = 7101.0037
Workdone = 7,101 J
B.) Workdone by force of friction on flight bag:
- 7,101 J (since the body moves at constant velocity)
C.)
Coefficient of kinetic friction (μ) = Frictional force / normal reaction)
μ = F / N
Frictional force, F = Workdone by friction / distance
F = 6200 / 318
F = 19.47N ;
Ff = weight of Flight bag = 70 N
N = Ff - Fsinθ
N = 70 - applied Force sinθ
N = 70 - 41sin57
N = 70 - 34.385493
N = 35.614506
μ = 19.47 / 35.614506
μ = 0.5466873