Answer:
[tex]1\ \text{W/m}^2[/tex]
[tex]0.0039\ \text{W/m}^2[/tex]
Explanation:
[tex]I_1[/tex] = Intensity of sound at 2 m away
Sound level = 120 dB
[tex]r_1[/tex] = 2 m
[tex]r_2[/tex] = 32 m
[tex]I_0[/tex] = Threshold of sound = [tex]10^{-12}\ \text{W/m}^2[/tex]
Sound level is given by
[tex]dB=10\log (\dfrac{I_1}{I_0})\\\Rightarrow I_1=10^{\dfrac{dB}{10}}I_0\\\Rightarrow I_1=10^{\dfrac{120}{10}}\times 10^{-12}\\\Rightarrow I_1=1\ \text{W/m}^2[/tex]
The intensity of sound at 2 m away is [tex]1\ \text{W/m}^2[/tex]
[tex]I_1=\dfrac{P}{4\pi r^2}[/tex]
[tex]I\propto \dfrac{1}{r^2}[/tex]
[tex]\dfrac{I_1}{I_2}=\dfrac{r_2^2}{r_1^2}\\\Rightarrow I_2=\dfrac{I_1r_1^2}{r_2^2}\\\Rightarrow I_2=\dfrac{1\times 2^2}{32^2}\\\Rightarrow I_2=0.0039\ \text{W/m}^2[/tex]
The intensity of the sound 32 m away is [tex]0.0039\ \text{W/m}^2[/tex]
Why doesn’t the force you exert when sitting on a chair cause the chair to move?
a. The floor exerts a balancing force on the chair.
b. The floor exerts too much force on the chair
c. The floor exerts an unbalancing force on the chair.
d. The floor exerts no force on the chair.
Answer:
the answer is A
Explanation:
help me do this question
Answer:
c20800
Explanation:
go to bear khana bro your book looks cheap go and study in durbar kanda school and take somee cash and do ash ah boy
what is plasma made of and what are its properties.
why do we need to study plasma in physics
Plasma is made up of about 90% water. It also has salts and enzymes.
Plasma has:
no fixed shape no fixed volume are less dense than liquids and solidsAnswer:
Plasma is made up of about 90% water . These are the properties of plasma. Plasmas have no fixed shape or volume, and are less dense than solids or liquids. Studying plasmas is critical to advance technology development for practical purposes as developing functional fusion reactors and to understand the processes in stars, planets and inter-stellar spaceI hope l helped you ❤❤Which of these is an example of chemical energy being converted to mechanical energy?
eating breakfast then walking to the bus.
turning on the radio
piling wood and then making a fire
Answer:
Eating breakfast then walking to the bus
a strong lightning bolt transfers about 25 C to earth. how many electrons are transferred?
Answer:
[tex]n = 1.563x {10}^{20} [/tex]
What is the difference between the geographic North Pole and the magnetic north pole?
Answer:
Magnetic north is the direction towards the north magnetic pole, which is a wandering point where the Earth's magnetic field goes vertically down into the planet
Explanation:
I searched it up lol
Which is a feature of a cladogram?BY MOHAMED
I GIVEING A !)) 100 point RIGHT NOW ASP
Answer:
Constructed cladograms all typically share certain key features: Root – The initial ancestor common to all organisms within the cladogram (incoming line shows it originates from a larger clade) Nodes – Each node corresponds to a hypothetical common ancestor that speciated to give rise to two (or more) daughter taxa.
Explanation:
Answer:
one feature of a cladogram is a branch that shows you relations among animals
Explanation:
Explain how sound travels from your vocal cords to your friend’s ear when you talk
Answer:
Your vocal cords vibrate and then travel through the air to your friends ear. ... loudness is a humans perception of sound intensity, as intensity of a sound wave increases the loudness of a sound wave increases.
~+lil more info+~
Sound waves enter the outer ear and travel through a narrow passageway called the ear canal, which leads to the eardrum. The eardrum vibrates from the incoming sound waves and sends these vibrations to three tiny bones in the middle ear.
~+. can i get brainlist? :) .+~
Which best illustrates projectile motion
A pictorial diagram of a person hopping sideways at 5 different positions. The start and end positions are on the ground. The correct option is D.
What is projectile motion?Projectile motion is the motion of an artifact thrown or projected into the air that is only affected by gravity's acceleration. The object is known as a projectile, and its path is known as its trajectory.
Any object that is cast, fired, flung, heaved, hurled, pitched, tossed, or thrown is considered a projectile.
Throwing a ball straight up, kicking a ball at an angle to the horizontal, or simply dropping things and letting them fall are all examples of projectile motion.
The pictorial diagram of a person hopping sideways in five different positions best illustrates projectile motion. The starting and ending points are on the ground.
Thus, the correct option is D.
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Your question seems incomplete, the missing options are:
A pictorial diagram showing a hot air balloon in four different positions, each the same height from the ground and equally spaced.A pictorial diagram with a rocket launched straight upward. The first three positions of the rocket are shown with equal spacing between them.A pictorial diagram with a person swimming and position shown in equal time intervals and equally spaced.A pictorial diagram of a person hopping sideways at 5 different positions. The start and end positions are on the ground.How many significant figures in 0.00850
Answer:
5
Explanation:
Plz di all plz i will give brainest and thanks to best answer do it right
Hamid is viewing an image of a bird produced by a set of concave lenses. What must be true about the image? It is a virtual image. It is upside down. It is larger than the actual bird. It is capable of being projected.
The true statement about the image formed by the concave lens is virtual.
Properties of image of formed by a concave lens
The properties of image of formed by a concave lens include the following;
The images are always;
virtual, erect, and diminishedThus, the true statement about the image formed by the concave lens is virtual.
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Answer:
it mf a i think
What factors affect the amount of potential and kinetic energy a roller coaster has
Answer:
As the roller coaster goes higher, more potential energy is increased in the roller coaster. Caused by gravity and the roller coaster's position, the potential energy is stored in the roller coaster. For example, this ball is at the top of a hill, where potential energy is at it's highest. Potential energy can be calculated by Potential Energy=Mass X Acceleration X Height.
Explanation:
The factor that impact the amount of potential and kinetic energy should be explained below.
Factor impact the amount of energy:Since the roller coaster should be high which there should be more potential energy and the same should be increased.
Due to the gravity and the position of the roller coaster the potential energy should be stored in the rolar coaster.
Just like when the ball is in the top of the hill when there is high potential energy so in this way it should be impacted.
learn more about energy here: https://brainly.com/question/12052751
Describe how the properties of sound waves change as they spread out in a spherical pattern.
To solve this we must be knowing each and every concept related to sound waves. Therefore, a sound waves change as they spread out in a spherical pattern, they go up and down.
What is sound waves?A sound is a type of energy or a vibration that moves through a material such as air or water. Sound may pass through with a gaseous medium as well. It is anything that is audible. The speed that sound varies depending on the medium.
A wave is a medium that transmits energy from one location to another. Waves are classified into three types: transverse waves, longitudinal waves, or surface waves. A sound waves change as they spread out in a spherical pattern, they go up and down.
Therefore, a sound waves change as they spread out in a spherical pattern, they go up and down.
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Which unmanned craft is used to collect data about bodies in space?
Answer:
space probe
Explanation:
Answer:
Space probe
~+ lil more info+~
Space probe is the unmanned craft used to collect data about bodies in space. Space probe is any unmanned, unpiloted spacecraft that is created to explore space and collect scientific data.
can i have brainlist? :)
The force of air particles over an area is ________
temperature.
pressure.
volume.
kelvins.
what is a gram used to measure
Answer:
The gram is the basic unit of measurement
Explanation:
You use it to weigh small items such as sugar, flour, coffee, and other items that are similar.
If you want to measure in grams using a scale is the most accurate solution.
(have a nice day!)
Electric power is to be generated by installing a hydraulic turbine-generator at a site 70 m below the free surface of a large water reservoir that can supply water at a rate of 1500 kg/s steadily. If the mechanical power output of the turbine is 800 kW and the electric power generation is 750 kW, determine the turbine efficiency and the combined turbine–generator efficiency of this plant. Neglect losses in the pipes.
Answer:
[tex]\eta_{turbine} = 0.777 = 77.7\%[/tex]
[tex]\eta_{combined} = 0.728 = 72.8\%[/tex]
Explanation:
First we calculate the power input to the turbine. The input power will be equal to the potential energy of water per unit time:
Input Power = [tex]P_{in} = \frac{Work}{Time} = \frac{Potential\ Energy\ of\ Water}{t} \\P_{in} = \frac{(mass)(g)(height)}{Time} = (mass flow rate)(g)(height)\\\\P_{in} = (1500\ kg/s)(9.81\ m/s^2)(70\ m)\\P_{in} = 1.03\ x\ 10^6\ W = 1030\ KW[/tex]
Now, for turbine efficiency:
[tex]\eta_{turbine} = \frac{Mechanical\ Power\ Out}{P_{in}}\\\\\eta_{turbine} = \frac{800\ KW}{1030\ KW}\\\\\eta_{turbine} = 0.777 = 77.7\%[/tex]
for generator efficiency:
[tex]\eta_{generator} = \frac{Power\ Generation}{Mechanical\ Power\ Out}\\\\ \eta_{generator} = \frac{750\ KW}{800\ KW}\\\\\eta_{turbine} = 0.9375 = 93.75\%[/tex]
Now, for combined efficiency:
[tex]\eta_{combined} = \eta_{turbine}\ \eta_{generator}\\\\\eta_{combined} = (0.777)(0.937)\\\eta_{combined} = 0.728 = 72.8\%[/tex]
Is it true that acceleration occurs when there is a change in speed
Answer:
Acceleration is the rate of change of velocity.
Explanation: For example, acceleration is measured in m/2^2 or meters per second squared. That can also be split up into 2 components. M/s is how speed is measured, and since acceleration is the rate of change of velocity, m/(s*s). You could say that since acceleration is m/s^2, it can also be represented as how much the speed increases over 1 second. if there was an acceleration of 3 m/s^2, the rate of change of speed would be 3m/s every second, meaning that the object would speed up 3m/s every second that passes by.
Hope this helps!
A duck is floating in a pond. How does Archimedes' description of the buoyant force explain why the duck
doesn't sink?
PLEASE HURRY
Answer:
The upthrust or buoyant force helps the duck doesn't sink.
For example, there is a duck which weighs 3 pounds and tree pints of water also weigh three pounds. In this case the volume of the duck is more than the volume of three pints of water, so the duck floats.
Hope it helps!<3
1 point
An unfortunate bug splatters against the windshield of a moving car.
Compared to the acceleration of the car, the acceleration of the bug is
Answer:the same
Explanation:their moving at the same speed and collapse
According to Newton's law, the force exerted by the bug and car is equal and opposite. Thus their acceleration decreases as mass increases. Therefore the acceleration of bug will be greater than that of the car.
What is acceleration?Acceleration, in physics is the rate of change in velocity. Thus it has the unit m/s². Newton's second law of motion states that the force acting on a moving body is the product of its mass and acceleration.
Hence F= m a indicates that the acceleration is in inverse proportionality with the mass. Thus a body with greater mass will have smaller acceleration but greater force.
According to third law of motion, an action have an equal opposite reaction. Thus the force exerted by the bug on the car and the force exerted by the car on bug are equal and opposite where, the bug will have greater acceleration due to its less mass.
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A weightlifter completes a series of lifts with a 700 N weight. In one lift, he raises the weight to a height of 2.5 m off the ground. The lift takes 0.60 s to complete. What power does the weightlifter have been performing this lift
Answer:
The output power the weightlifter is 2916.67 W.
Explanation:
Given;
weight lifted, W = 700 N
height the weight is lifted, h = 2.5 m
time taken to lift the weight, t = 0.60 s
The output power the weightlifter is calculated as;
Power = Energy applied / time taken
Energy applied = weight lifted x height the weight is lifted
Energy applied = 700 x 2.5
Energy applied = 1750 J
Power = 1750 / 0.6
Power = 2916.67 J/s = 2916.67 W.
Therefore, the output power the weightlifter is 2916.67 W.
A stone takes 5.4 seconds to fall from the top of a cliff. The cliff is
meters high.
143
53
286
573
Answer:
143
Explanation:
Using one of the 3 fundamental equations in physics, y=vo*t+1/2gt^2, we can use this equation to find the total distance that was traveled.
Acceleration due to gravity is always 9.8m/s^2 and time is 5.4s, we also have no initial velocity.
Given this, we can plug in the known variables.
y=0t+1/2*9.8*5^2
simplify,
y=4.9*5.4^2
y=4.9*29.16
y=142.884m which we can round up to 143 meters
Final Answer: 143 meters
What is the Kinetic Energy of a 150 kg object that is moving with a speed of 15 m/s?
Group of answer choices
1. KE = 22,050J
2. KE = 1,125J
3. KE = 33,750J
4. KE = 16875J
why we can not measure the total amount of heat energy that a body contains
Answer:
... As has been previously discussed, heat is not something that is contained in an object.
Explanation:
Two masses are placed close to each other. How will the gravitational force acting on the masses change if the distance between the two masses is doubled?
Answer:
If the mass of both of the objects is doubled, then the force of gravity between them is quadrupled; and so on. Since gravitational force is inversely proportional to the square of the separation distance between the two interacting objects, more separation distance will result in weaker gravitational forces.what power is transmitted by 2A flowing across 5V
Answer:
[tex]\huge\boxed{10\:watts}[/tex]
Explanation:
Power = Current × Voltage
P = I × V
P = 2 × 5
P = 10 watts
What does a represent??
I need it quick
Answer:
a is acceleration
Explanation:
A bicyclist with a mass of 50 kg is traveling at a rate of 30 m/s. It accelerates to a rate of 50 m/s in 5 seconds. What is the net force acting on the bicycle?
Answer:
200 N
Explanation:
There is only two needed factors in play here; the mass and acceleration
According to Newton's 2nd Law: F = m*a
Now Acceleration is Velocity over Time, so we have another factor in play: Acceleration = 50-30/5 = 20/5 = 4m/s^2
Net force = (50 kg)(4 m/s^2) = 50*4 = 200 Newtons
Which of the following units are the Standard International units for
displacement?
A. Meters (m)
B. Meters per Second (m/s)
C.Meters per Second Squared (m/s2)
D. Seconds per Meter (s/m)
