Answer:
Part A
The sound intensity at the location 150 from the firework = 4.3[tex]\overline 5[/tex] W/m²
Part B
The power the firework is emitting is approximately 1,231.5 kW
Explanation:
Part A
The data of the firework sound heard by the two friends are;
Let 'A' represent the location of the friend at a point 150 m from the fireworks and let 'B' represent the location of the friend watching from a distance of 700 m from the firework
The distance of 'A' from the sound, r₁ = 150 m
The distance of 'B' from the sound, r₂ = 700 m
The intensity at which 'B' hears the sound, I₂ = 0.2 W/m²
The relationship between sound intensity and distance is given as follows;
[tex]\dfrac{I_2}{I_1} = \left (\dfrac{r_1}{r_2} \right )^2[/tex]
[tex]\therefore {I_1} = \dfrac{I_2}{ \left (\dfrac{r_1}{r_2} \right )^2} = I_2 \times \left (\dfrac{r_2}{r_1} \right )^2[/tex]
Plugging in the values gives;
[tex]\therefore {I_1} = 0.2 \times \left (\dfrac{700}{150} \right )^2 = \dfrac{196}{45} = 4.3\overline 5[/tex]
The sound intensity at location 'A', I₁ = 4.3[tex]\overline 5[/tex] W/m²
Part B
The relationship between power, 'P', and intensity, 'I', is presented as follows;
[tex]I = \dfrac{P}{4 \cdot \pi \cdot r^2}[/tex]
P = I·4·π·r² = 4·I·π·r²
Therefore, at point 'A', where the distance, r₁ = 150 m, and the intensity, I₁ = 4.3[tex]\overline 5[/tex] W/m², we have;
P = 4 × 4.3[tex]\overline 5[/tex] W/m² × π × (150 m)² = 1231504.32021 W
The power the firework is emitting, P ≈ 1,231.5 kW.
any tips for an ollie ?
Answer:
skateboard mid-ollie is being actively steered. This is exactly what makes doing an ollie so hard. It's not enough to get the skateboard up into the air - you also have to steer it while it's in the air. You should keep your hands up in the hair a bit to help with balance, scrunch your legs a bit down to have a proper and effective jump. wear nee pads incase you dont fix the landing. Practice jumping on ur skate board tho, if u jump at it without knowing much youll just get hurt.
Explanation:
How much work is done when 300 N of force is used to lift the dog 1.5 m?
Answer:
450N
Explanation:
Work done=Force*distance
You slide out of a car seat and as you touch the metal door a spark jumps between your hand and the door. Describe how the spark formed
Answer: Your body sliding against the car seat created friction, making it created potential energy. The friction is a form of electricity, and the car doors metal is a conductor of electricity. That potential energy was turned into kinetic once the metal attracted the electricity, thus making a spark.
Hope this helps ^_^
How do you calculate the total resistance in a series circuit with more than one resistor
Answer:
You add up all the individual resistances of the resistors in the series circuit to get the total resistance of the circuit
Explanation:
A series circuit is a circuit that has most of its components connected end-to-end
following what was stated above, in a series circuit, the resistors are connected end to end. This means that the current that flows out from one of the resistors flows into the next one. As a result of this, the current through all the resistors is the same.
To get the total equivalent resistance in a series circuit, you add up all the individual resistances of the resistors in the series circuit. This should give you the total resistance in the circuit.
i.e
Total resistance = R1 + R2 + R3 ....
Can someone please help me with history.
Answer:
Yes my name is Axelrod I can help you
An electromagnet is a device that uses an electric current to produce a magnetic field.
Electromagnets are typically composed of a piece of metal wrapped with wire and connected to a battery. The battery provides the electric current, and the loops or coils of wire enhance the magnetic field. The more loops there are, the stronger the magnetic field.
When electric current flows through the electromagnet, the metal core becomes magnetized, so it possesses a north pole and a south pole.
Motors place electromagnets inside of permanent magnets as shown below.
However, motors are designed so that the polarity of the electromagnet constantly flips. That is, the north pole becomes the south pole, and the south pole becomes the north pole, every time the electromagnet turns 180 degrees.
Why is it designed this way?
A.
to conserve the energy in the battery
B.
to constantly polarize the field magnet
C.
so the electromagnet will continuously turn
D.
so the magnetic field will get stronger
The reason why motors are designed so that the polarity of the electromagnet constantly flips.is
C. so the electromagnet will continuously turn
Why is motor designed that wayThe reason motors are designed so that the polarity of the electromagnet constantly flips is to continuously turn the electromagnet. This allows the motor to rotate continuously, rather than becoming stuck in one position.
The flipping of the polarity causes the electromagnet to attract and repel from the permanent magnets, creating a rotating motion.
Therefore, the correct answer is C.
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a vehicle is moving with 20m/s towards the east and another is moving 15m/s towards the west
Answer:
5 m/s
Explanation:
Given that,
A vehicle is moving with 20m/s towards the east and another is moving 15m/s towards the west.
It is assumed to find the resultant velocity of the vehicle. Let east side is positive and west is negative. So,
[tex]v=v_1+v_2\\\\=20+(-15)\\\\=5\ m/s[/tex]
Hence, the resultant velocity of the vehicle is equal to 5 m/s.
please help me out i'm so depressed and such a failure
how does the brightness of the lamp (L) vary if we dispalce the cursor (C) of the rheostat
a)Towards A
b) Towards B
Answer:
ok so first ur not a failure and its okay don't be so hard on ur self
<3Se tiene un objeto que oscila con MAS. Si la amplitud del movimiento es de 15 cm y el periodo es de 2 seg, encontrar las magnitudes de la velocidad y la aceleración cuando: a) x= 0 cm b) x=7,5 cm Por favor, ayúdenme es para hoy :c
Answer:
a) v = 0, a = - 15 pi²
b) v = - 40.8 cm / s, a = -74.2 cm / s
Explanation:
the simple harmonic motion is described by the expression
x = A cos (wt + Ф)
in that case they indicate the amplitude of the movement
A = 15 cm
angular velocity and period are related
w = 2π / T
w = 2π/ 2
w = π rad / s
speed is defined by
v = dx / dt
v = -A w sin (wt + Ф)
acceleration is defined by
a = dv / dt
a = - A w² cos (wt + Ф)
In order to evaluate this expression we must know the value of the phase constant (Ф) that meets the initial conditions, the most common thing is that the system is released, v = 0 for y = 0 s, let's use the speed equation
v = -A w sin (0+ Ф)
for this expression to be zero, the sine must be zero, so
Ф= 0
now let's write the equations for our case
v = - 15 π sin (π t)
a = - 15 π² cos (π t)
a) for x = 0
v = 0
a = - 15 pi²
b) for x = 7.5 cm
Let's find out how long it takes to get to this position
x = 15 cos (π t)
7.5 / 15 = cos π t
pi t = cos⁻¹ 0.5
t = 1.047/π
don't forget that the angles are in radians
t = 0.333 s
now let's look for speed and acceleration
v = - 15 π sin (π 0.333)
v = - 40.8 cm / s
a = - 15 π² cos (π 0.333)
a = -74.2 cm / s
Help!!!
Where can the hoses be attached in order to provide water to a fire engine? (There may be more than one correct answer.)
house faucet
hydrant
generator
pumper truck
Answer:
Explanation:
Hydrant
What type of specialized cell in the eye is used for detecting low levels of light?
Answer:
There are about six to seven million cones in a human eye and are most concentrated towards the macula. Cones are less sensitive to light than the rod cells in the retina (which support vision at low light levels), but allow the perception of color.
Answer:
Rods
Explanation:
There are about six to seven million cones in a human eye and are most concentrated towards the macula. Cones are less sensitive to light than the rod cells in the retina (which support vision at low light levels), but allow the perception of color.
ASAP!!!
What is the purpose of a heavy stream appliance?
provides breathable air from attached air tanks
focuses the fluid flow into a heavier stream
moves or removes smoke and gases from buildings and passageways
removes citizens from burning or hazardous structures
Answer:
B is the answer.
Explanation:
I am doing the same Assignment.
Which type of comb would be best to use in the winter, a plastic comb or a glass comb? Explain using the Triboelectric series.
Answer:
I'm not sure how to use it using the Series, but it would be the plastic comb
Explanation:
In the winter, it's likely to be cold and the glass would absorb that energy, also making it cold. in order to be able to hold it, you would need something warm, thus making the plastic one the better option as it is less likely to absorb the cold energy
If a person meets an accident, which of the following factors will have more effect on his Kinetic energy and hence on the fatality of the accident?
A.velocity of the vehicle
B.Mass of the vehicle
Answer:
b
Explanation:
A 50,000 kg train is rolling on its own down the track at 5 m/s. You grab the rope trailing behind it, and exert a stopping force of 2000 N. How long does it take to stop the train?
Answer:
t = 125 seconds
Explanation:
Given that,
The mass of a train, m = 50,000 kg
Initial speed, u = 5 m/s
Stopping force, F = 2000 N
We know that,
Force, F = ma
Where
a is acceleration
[tex]F=\dfrac{m(v-u)}{t}\\\\t=\dfrac{m(v-u)}{F}\\\\t=\dfrac{50000(0-5)}{-2000}\\\\t=125\ s[/tex]
So, it will take 125 seconds to stop the car.
help.....please science
Answer:
please mark me brainliest
Explanation:
ohm
The SI-derived unit of electric resistance is the ohm, which is defined as a volt per ampere.
Answer:
I cant see that
What is only found in plant cells??
Cell membrane , nucleus, cell wall , vacuole.
which one !!!
define one ampere current electricity
providing trademark protection
Answer:
what are you asking exactly?
Determine the resistance of 100m of copper cable whose cross-sectional area is 1.5mm2
True or False. The Magnitude of the induced voltage in a coil of wire depends on how quickly the magnetic flux through the coil of wire changes.
Answer:
Yes, its true
Explanation:
hdheheishdhieijzuwhs
Answer: yes its true
Explanation:
nmo
Which is closest to the Earth?
A. Moon
B. Sun
C. Mars
D. Venus
Answer:
A. Moon
Explanation:
The Moon is hundreds of thousands of miles away from the Earth while the other options are hundreds of millions of miles away.
A 20.0 Ohm and 60.0 Ohm resistor
are connected in series to a 9.00 V
battery. What is their equivalent
resistance?
(Unit = Ohms)
Answer:
for resistors in series, add the resistances to get their equivalence. The answer is
80.0 Ohms
A 3kg object moving at 4 m/s encounters a 20 N resistive force over a duration of 0.20 seconds. The impulse experienced by this object is _____
Answer:
the impulse experienced by this object is 4 Ns
Explanation:
Given;
mass of the object, m = 3 kg
velocity of the object, v = 4 m/s
resistive force, F = 20 N
duration of impact, t = 0.2 s
The impulse experienced by this object is calculated as follows;
J = F x t
J = 20 x 0.2
J = 4 Ns
Therefore, the impulse experienced by this object is 4 Ns
Bajo la acción del viento una puerta gira un ángulo de 90° en 5 s. Calcular su velocidad angular y la velocidad lineal de los puntos del borde
si el ancho de la puerta es de 50 cm. R. 0,314 rad/s, 0,157 m/s.
When a substance is poured from one container to another, its shape changes but its volume does not, what state of matter is the substance in?
A. Plasma
B. Liquid
C. Gas
D. Solid
Answer: When a liquid substance is poured into a vessel, it takes the shape of the vessel, and, as long as the substance stays in the liquid state, it will remain inside the vessel. Furthermore, when a liquid is poured from one vessel to another, it retains its volume (as long as there is no vaporization or change in temperature) but not its shape.
Explanation: A solid has a definite shape and volume. A liquid has a definite volume, but takes the shape of its container. A gas lacks either a defined shape or volume. Plasma is similar to a gas in that its particles are very far apart, but a gas is electrically neutral and plasma has a charge.
Answer:
B
Explanation:
Liquid
In a symbiotic relationship,
a. one organism benefits while its host gets nothing in return.
b. bacteria takes food from your stomach, but does nothing for you.
c. both organisms involved benefit or are neutrally affected.
d. your body produces vitamins and then uses them for nutrition
In a symbiotic relationship, both organisms involved benefit or are neutrally affected. Symbiosis is a close and long-term interaction between two different species.
The term "symbiosis" encompasses mutualism, commensalism, and parasitism. In mutualism, both organisms benefit from the interaction, such as in the case of bees and flowers where bees obtain nectar and pollen while also helping flowers to pollinate.
In commensalism, one organism benefits while the other is neither helped nor harmed, such as remora fish that attach to sharks for transportation and feeding on scraps left by the shark. In parasitism, one organism benefits while the other is harmed, such as ticks that feed on blood from a host animal.
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skater spins over a point at a speed of 3.0 rotations per second then the momentum of inertia is 0.60 kg.M2, what is its angular momentum?
Answer:
[tex]L=11.3\ kg-m^2/s[/tex]
Explanation:
Given that,
Angular speed of a skater, [tex]\omega=3\ rot/s=18.84\ rad/s[/tex]
The moment of inertia of the skater, I = 0.6 kg-m²
We need to find the angular momentum of the skater. The formula for the angular momentum of the skater is given by :
[tex]L=I\omega[/tex]
Substitute all the values,
[tex]L=0.6\times 18.84\\\\L=11.3\ kg-m^2/s[/tex]
So, its angular momentum is equal to [tex]11.3\ kg-m^2/s[/tex].
¿Qué pasa en nuestro cerebro cuando tomamos decisiones? Ejemplo: Estoy tocando una plancha caliente, y saco la mano rápidamente, ¿que paso en mi cerebro?
Answer:
Debido a la información de las neuronas sensoriales al cerebro.
Explicación:
Cuando toco una plancha caliente, extiendo la mano rápidamente porque las neuronas sensoriales presentes en la piel de nuestro cuerpo envían señales al sistema nervioso central, es decir, al cerebro. El cerebro toma decisiones de acuerdo con los estímulos y envía instrucciones a través de las neuronas motoras a los músculos para retirar las manos del hierro caliente a fin de evitar efectos nocivos en la piel debido al calor. El lóbulo frontal es una parte del cerebro que controla la personalidad, la toma de decisiones y el razonamiento.
A child drops a bouncy ball. Each time it bounces, it reaches a lower height until it eventually
stops. Describe the energy transfers and explain why the ball lowered in height
Answer:
the ball's was lowered because of the gravitational force and because of the friction force's