Answer:
A sound wave is called a longitudinal wave because compressions and rarefactions in the air produce it. The air particles vibrate parallel to the direction of propagation.
A bus contains a 1500 kg flywheel (a disk that has a 0.600 m radius) and has a total mass of 10,000 kg.
(a) Calculate the angular velocity the flywheel must have to contain enough energy to take the bus from rest to a speed of 20.0 m/s, assuming 90.0% of the rotational kinetic energy can be transformed into translational energy.
(b) How high a hill can the bus climb with this stored energy and still have a speed of 3.00 m/s at the top of the hill? Explicitly show how you follow the steps in the Problem-Solving Strategy for Rotational Energy.
Answer:
Explanation:
moment of inertia of flywheel = 1/2 m R²
= .5 x 1500 x .6²
= 270 kg m²
If required angular velocity be ω
rotational kinetic energy = 1/2 I ω²
= .5 x 270 x ω² = 135 ω²
kinetic energy of bus when its velocity is 20 m/s
= 1/2 x 10000 x 20²
= 2000000 J
Given 90 % of rotational kinetic energy is converted into bus's kinetic energy
135 ω² x 0.9 = 2000000 J
ω²=16461
ω = 128.3 radian /s
b )
Let the height required be h .
Total energy of bus at the top of hill = mgh + 1/2 m v²
m ( gh + .5 v²)
= 10000 ( 9.8h + .5 x 3²)
From conservation of mechanical energy theorem
10000 ( 9.8h + .5 x 3²) = 2000000
9.8h + .5 x 3² = 200
9.8h = 195.5
h = 19.95 m .
Dr. Kirwan is preparing a slide show that he will present to the executive board at tonight's committee meeting. He places a 3.50-cm slide behind a lens of 20.0 cm focal length in the slide projector. A) How far from the lens should the slide be placed in order to shine on a screen 6.00 m away? B) How wide must the screen be to accommodate the projected image?
Answer:
A) d_o = 20.7 cm
B) h_i = 1.014 m
Explanation:
A) To solve this, we will use the lens equation formula;
1/f = 1/d_o + 1/d_i
Where;
f is focal Length = 20 cm = 0.2
d_o is object distance
d_i is image distance = 6m
1/0.2 = 1/d_o + 1/6
1/d_o = 1/0.2 - 1/6
1/d_o = 4.8333
d_o = 1/4.8333
d_o = 0.207 m
d_o = 20.7 cm
B) to solve this, we will use the magnification equation;
M = h_i/h_o = d_i/d_o
Where;
h_o = 3.5 cm = 0.035 m
d_i = 6 m
d_o = 20.7 cm = 0.207 m
Thus;
h_i = (6/0.207) × 0.035
h_i = 1.014 m
If you're the white mouse, what will you do in order for you to survive
Answer:
If I was the white mouse, I would either find somewhere to hide that matches my fur color to camoflouge with or dig into the dirt so less visible.
To find white colour habitat.
What will I do for my survival?If I was the white mouse, I would find white colour place for living because in that white colour the predators can't see me and i will be safe from them so we can conclude that finding white colour habitat is the best choice to safe myself.
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WORTH 15 POINTS WILL GIVE BRAINLIEST
What is the mechanical advantage of a handle on a water well that requires 5 newtons of force to lift a 40-Newton bucket of water?
200
8
0.125
12.5%
Option B. The mechanical advantage of a handle on a water well that requires 5 newtons of force to lift a 40-Newton bucket of water is 8.
Mechanical advantage is a measure of the force amplification completed by means of the usage of a device, mechanical tool or gadget device. The device trades off input forces towards motion to gain a preferred amplification in the output pressure.
The version for this is the regulation of the lever. The mechanical advantage is the degree how which tons of force is increased with the aid of using a device or gadget. it is equal to the pressure exerted with the aid of the tool or system divided via the carried-out effort.
calculation:-
Mechanical advantage = load/effort
= 40/5
= 8
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3. What does an object at rest and an object moving at constant velocity have in common?
A fall thrown vertically upwards with a speed
of 20 ms-¹ from the top of a tower reaches
the earth in 8seconds. find the height of the
tower.
take g= 10ms-²
Answer:
Height of tower = 480 meter
Explanation:
Given:
Initial velocity = 20 m/s
Time taken to reach ground = 8 second
So,
Final velocity = 0 m/s
Acceleration due to gravity = 10 m/s²
Find:
Height of tower
Computation:
s = ut + (1/2)(g)(t)²
s = (20)(8) + (1/2)(10)(8)²
s = 160 + (1/2)(10)(64)
s = 160 + (10)(32)
s = 160 + 320
s = 480 meter
Height of tower = 480 meter
Which of these statements explains why we have day and night? [1] The Earth orbits the Sun once a day The Sun orbits the Earth once a day. The Sun spins on its axis once a day. The Earth spins on its axis once a day.
Answer:
The Earth spins on its axis once a day.
Explanation:
In simple words,The Earth revolves on its axis once every 24 hours and circles the sun once every 365 days. The Earth's rotation on its axis, not its orbit throughout the sun causes day as well as night. The word 'one day' refers to the period it requires the Earth to spin entirely on its axis, which involves both day as well as night.
If a body is thrown up with an initial velocity 'u' and covers a maximum height of 'h' , then 'h' is equal to u²/2g
Explain in detail.
Answer:
1/2 m u^2 initial Kinetic Energy of body
m g h Potential Energy body attains as it rises to height
1/2 m u^2 = m g h conversion of KE to PE
h = u^2 / ( 2 g)
who is the first physicist and what did he invented?
Answer:
hippocrates
I guess..........
A go-cart and rider have a mass of 100 kg. If the cart accelerates at 5 m/s2 during a 25 m sprint, how much work did the cart do
Answer:20watts
Explanation:
Answer:
The solution is given below
Explanation:
The computation is shown below;
We know that
Work done = Fs cosθ
But before that we need to determine the force i.e.
We know that
Force (F) = mass (m) × Acceleration (a)
= 100 × 5
= 500 N
Now, work done by the go-cart is
Work done (W) = Fs cosθ
= 500 × 25 × cos(0°)
= 500 × 25 × 1
= 12,500 J
Building a space station, in which astronauts would live for a considerable time, is essential even if the space station project were to contribute no new knowledge about space or Earth that could not otherwise be obtained. For future missions to explore Mars, we will need the medical knowledge that the space station project will give us about the limits of human capacities to live in spacecraft for an extended time.
The argument makes the assumption that
(A) the exploration of Mars will be carried out by people traveling in spacecraft and not by robots alone
(B) the capacities of astronauts are typical of those of ordinary human beings
(C) no unforeseen medical problems will arise on the first mission to explore Mars
(D) a mission to Mars will be the first of many missions that will explore the solar system
(E) living in spaceship for an extended time presents insurmountable medical problems
Answer:
The argument make the assumption that;
(A) The exploration of Mars will be carried out by people travelling in spacecraft and not by robots alone
Explanation:
The argument is made for the importance of a space station where astronauts live for an appreciable time to aid in the understanding of human capacities for living in the space so as to increase the successful space travel human to Mars, which is a distance further than the Moon and therefore, will require sufficient time travel
This Is Science , please help it’s due at 3 , but I dont mind if its a little late.
Answer:
uhm you can get all these answers from go ogle but just so you dot get in trouble click the tree dots at the top right of your screen (this is if your using crome) and go to history click the square and there should be a delete thing
Explanation:
Answer:
4. I and II 9. tornado
Explanation:
Why does the golf ball sink in
water, while the beach ball
floats?
A- The beach ball weighs less than
the golf ball
B- The golf ball has a higher density
than the beach ball
C- The beach ball has a higher
density than the golf ball
D- The golf ball has more mass than
the beach ball
A 1500 kg car accelerats from 55.0 m/s to 90.0 m/s. Calculate the impulse experienced by the car
Answer:
The impulse experienced by the car is 52,500 kg.m/s.
Explanation:
Given;
mass of the car, m = 1500 kg
initial velocity of the car, u = 55 m/s
final velocity of the car, v = 90 m/s
The impulse experienced by the car is the change in linear momentum, calculated as follows;
J = ΔP = mv - mu
ΔP = m(v - u)
ΔP = 1500(90 - 55)
ΔP = 52,500 kg.m/s
Therefore, the impulse experienced by the car is 52,500 kg.m/s.
What is another name for constructive interference?
A. Up
B. Down
C. Reinforcement
D. Cancellation
How is it possible a plant can sustain itself for 70 years locked inside a jar ?
Answer:
If you are talking about the experiment in which mouse and plants are kept in a closed glass jar in sunlight so in that case, they both survive because the CO2 released by the respiration of mouse is being utilized by the plants and fixed ( phosynthesis) and O2 is released as by product, which is taken by the mouse for respiration.
What type of reaction results in the formation of a salt?
A specified volume of space contains an electric field for which the magnitude is given by E=E0cos(ωt). Suppose that E0 = 20 V/m and ω = 1.0 × 107 s−1. What is the maximum displacement current through a 0.40 m2 cross-sectional area of this volume?
Answer: [tex]0.708\ mA[/tex]
Explanation:
Given
[tex]E_o=20\ V/m[/tex]
[tex]\omega =10^7\ s^{-1}[/tex]
Cross-sectional area [tex]A=0.40\ m^2[/tex]
Current density is given by
[tex]J=\epsilon_o \dfrac{dE}{dt}[/tex]
Displacement current
[tex]\Rightarrow I=JA\\\Rightarrow I=8.854\times 10^{-12}\times 20\times 10^7\times 0.4\\\Rightarrow I=0.708\times 10^{-3}\ A[/tex]
The required value of the maximum displacement current of the given space is [tex]7.08 \times 10^{-4} \;\rm A[/tex].
Given data:
The intensity of electric field is, [tex]E_{0}=20 \;\rm V/m[/tex].
The angular frequency of electric field is, [tex]\omega=1.0 \times 10^{7} \;\rm s^{-1}[/tex].
The cross-sectional area of space is, [tex]A =0.40 \;\rm m^{2}[/tex].
In the given problem, the instantaneous electric field is given by [tex]E = E_{0} \times cos(\omega t)[/tex]
So, the expression for the current density is,
[tex]J= \epsilon_{0} \times \dfrac{dE}{dt}[/tex]
Here, [tex]\epsilon_{0}[/tex] is the permittivity of free space. Solving as,
[tex]J= \epsilon_{0} \times \dfrac{d(E_{0} \times cos(\omega t))}{dt}\\\\J= -\epsilon_{0} \times E_{0} \times \omega \times sin(\omega t)[/tex]
And the expression for the maximum displacement current is,
[tex]I = J \times A[/tex]
And the maximum displacement current is possible only when, J is positive and J will be positive for [tex]sin(\omega t)=-1[/tex].
Then solving as,
[tex]I = (-\epsilon_{0} \times E_{0} \times \omega \times sin(\omega t)) \times A\\\\I = (-8.85 \times 10^{-12} \times 20 \times (1.0 \times 10^{7}) \times (-1)) \times 0.40\\\\I = 7.08 \times 10^{-4} \;\rm A[/tex]
Thus, we can conclude that the required value of the maximum displacement current of the given space is [tex]7.08 \times 10^{-4} \;\rm A[/tex].
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How are frequency, wavelength, and energy related? Choose all that apply.
Explanation:
The energy of a wave is given by :
[tex]E=\dfrac{hc}{\lambda}[/tex]
Where
h is Planck's constant
c is the speed of light
[tex]\lambda[/tex] is wavelength
Energy is inversely proportional to wavelength. Also, the relation between frequency and wavelength is inverse.
If the frequency is high, the wavelength will be shorter.
Hence, the correct options are :
Higher frequencies have shorter wavelengths.
Shorter wavelengths have lower energy.
Lower frequencies have lower energy.
What is a pulley and the how does it make lifting heavy loads easier?
What is the highest Mountain, and where is it?
Answer:
Mount Everest is Earth's highest mountain above sea level, located in the Mahalangur Himal sub-range of the Himalayas. The China–Nepal border runs across its summit point. Its elevation of 8,848.86 m was most recently established in 2020 by the Nepali and Chinese authorities.
Explanation:
True or false. There is only an induced voltage in a coil of wire if the magnetic flux through the coil of wire changes.
Select the correct answer.
What does AC stand for in physics?
O A. alternating current
OB. alternative circuit
OC. alternating composition
OD. all charge
A solenoid coil 10cm long has 40 turns cm-1. The current rises from zero to its maximum value of 5.0000 A and 0000.01s when the switch is closed. Find the energy stored in magnetic field if the area of cross section of solenoid be 28 centimeter square.
Answer:
Explanation:
Energy stored in a solenoid per unit volume = B₀² / (2μ₀)
B₀= μ₀ n I₀
n is no of turns per unit length .
Energy stored in a solenoid per unit volume = ( μ₀ n I₀)² / (2μ₀)
=μ₀n²I₀²/2
n = 40 turns / cm = 40 x 100 turns per meter.
I₀ = 5000A .
Putting the values
Energy stored in a solenoid per unit volume
= 4π x 10⁻⁷ x 40 x 10² x 5000² /2
= 1256 J/ m³
Volume of solenoid = cross sectional area x length
= 28 x 10⁻⁴ x .10 = 2.8 x 10⁻⁴ m³
Total energy stored = 1256 J / m³ x 2.8 x 10⁻⁴ m³
= .35 J .
Explain the effects of expansion of water on aquatic life
Answer:
The anomalous expansion of water helps preserve aquatic life during very cold weather. When temperature falls, the top layer of water in a pond contracts, becomes denser and sinks to the bottom. If the temperature falls further, the top layer expands and remains on the top till it freezes.
A 140 g tennis ball travelling 30° east of north at 15 m/s is struck by a tennis racquet, giving it a velocity of 25 m/s, west. What are the magnitude and direction of the impulse given to the ball? Include a labelled diagram.
Answer:
The magnitude of the impulse is 1.4 Ns in the West direction.
Explanation:
The impulse equation is given by:
[tex]\Delta p=m\Delta v[/tex]
Where:
m is the mass of the ballΔv is the difference in velocitySo we will have:
[tex]\Delta p=0.140(25-15)[/tex]
[tex]\Delta p=1.4\: Ns[/tex]
Therefore, the magnitude of the impulse is 1.4 Ns in the West direction.
I hope it helps you!
A 12 kg ball is rolling with a velocity of 10 m/s. How much kinetic energy does the ball have?
Answer:
600 J
Explanation:
KE = 1/2 mv^2
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:
I reckon towards b. Let me know if im right
What do diffraction and refraction have in common? They both involve interference. They both involve wave interactions. They both involve reflection. They both involve construction.
Answer:
They both involve wave interactions.
Explanation:
Diffraction is defined as the bending of waves around obstacles. Refraction can be defined as the bending of the light when it transfers from one substance to another. The main similarity between the diffraction and refraction is that both involves the interaction of the waves with the substance and also causes the waves to bend and change their direction. Hence, they both involve wave interaction is the correct option.
What diffraction and refraction have in common is that they both involve wave interactions. This is further explained below.
What are diffraction and refraction?When waves travel from one medium to another and refract, This causes them to change direction. while Diffraction is simply defined as the bending of waves around barriers.
In conclusion, diffraction and refraction are properties of waves.
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Our entire ______ _____
is built in the backbone of metals.
Answer:
modern world
Explanation:
