Answer:
[tex]-20.0 kg m^2/s[/tex]
Explanation:
The angular momentum of an object in rotation is given by
[tex]L=I \omega[/tex]
where
I is the moment of inertia
[tex]\omega[/tex] is the angular speed
In this problem, initially we have
[tex]I=2 kg m^2[/tex] is the moment of inertia of the wheel
[tex]\omega_i = 6.0 rad/s[/tex] is the initial angular speed
So the initial angular momentum is
[tex]L_i = I\omega_i = (2)(6.0)=12 kg m^2/s[/tex]
Later, a counterclockwise torque of
[tex]\tau=-5.0 Nm[/tex] is applied
So the angular acceleration of the wheel is:
[tex]\alpha = \frac{\tau}{I}=\frac{-5.0}{2}=-2.5 rad/s^2[/tex] in the direction opposite to the initial rotation.
As a result, the final angular velocity of the wheel will be:
[tex]\omega_f = \omega_i + \alpha t[/tex]
where
t = 4.0 is the time interval
Solving,
[tex]\omega_f = +6.0 +(-2.5)(4.0)=-4 rad/s[/tex]
which means that now the wheel is rotating in the counterclockwise direction.
Therefore, the new angular momentum of the wheel is:
[tex]L_f = I\omega_f =(2)(-4.0)=-8.0 kg m^2/s[/tex]
So, the change in angular momentum is:
[tex]\Delta L=L_f - L_i = (-8.0-(12))=-20.0 kg m/s^2[/tex]
Which colors of light represents the lowest visible frequency?
Answer:
Red
Explanation:
Red is a colour which has the lowest frequency. Violet has the highest frequency. Frequency has a direct relationship with energy. This means the higher the frequency, the higher the energy. Red has the lowest energy of all the colors too.
The frequency and Energy has an inverse relationship with the wavelength.
However Red has the longest wavelength of about 620 - 780 nanometer.
a uniform disc and hollow right circular cone have the same formula for their moment of inertia when rotating about the central axis why is it so?
Answer:
This is as a result that about the central axis a collapsed hollow cone is equivalent to a uniform disc
Explanation:
The integration of the differential mass of the hollow right circular cone yields
[tex]I=\int\limits dmr^2 = \int\limits^a_b {\frac{2Mxr^2}{R^2 +H^2} } \, dx = \frac{2MR^2dx}{(R^2 +H^2)^2} \frac{(R^2 +H^2)^2}{4} = \frac{1}{2}MR^2[/tex]
and for a uniform disc
I = 1/2πρtr⁴ = 1/2Mr².
Final answer:
Both a uniform disc and a hollow right circular cone have the same formula for their moment of inertia when rotating about the central axis because their shapes and mass distributions result in similar rotational behavior.
Explanation:
Both a uniform disc and a hollow right circular cone have the same formula for their moment of inertia when rotating about the central axis because their shapes and distributions of mass result in similar rotational behavior.
The moment of inertia depends on the distribution of mass around an axis of rotation. In both objects, the mass is distributed symmetrically about the central axis, resulting in similar moment of inertia values.
For a uniform disc, the moment of inertia is given by the formula I = 1/2 MR², where M is the mass of the disc and R is its radius. Similarly, for a hollow right circular cone, the moment of inertia is also given by the formula I = 1/2 MR², where M is the mass of the cone and R is the radius of its base.
Hurricanes can involve winds in excess of 100 km/h at the outer edge. Make a crude estimate of the energy of such a hurricane, approximating it as a rigidly rotating uniform cylinder of air (density 1.3 kg/m3) of radius 88 km and height 4.4 km .
Answer:
[tex]2.7\cdot 10^{16} J[/tex]
Explanation:
We can approximate the hurricane as a rotating uniform cylinder, so its energy is the rotational kinetic energy, given by:
[tex]E=\frac{1}{2}I\omega^2[/tex] (1)
where
I is the moment of inertia
[tex]\omega[/tex] is the angular velocity
The moment of inertia of a cylinder rotating about its axis is
[tex]I=\frac{1}{2}MR^2[/tex]
where
M is the mass
R is the radius
So formula (1) can be written as
[tex]E=\frac{1}{2}(\frac{1}{2}MR^2)\omega^2=\frac{1}{4}MR^2\omega^2[/tex] (2)
For an object in rotation, the linear speed at the edge is related to the angular velocity by
[tex]v=\omega R[/tex]
So we can rewrite (2) as
[tex]E=\frac{1}{4}Mv^2[/tex]
where we have:
[tex]v=100 km/h = 27.8 m/s[/tex] is the speed at the edge of the hurricane
We have to calculate the mass of the cylinder. We have:
[tex]R=88 km = 88,000 m[/tex] (radius)
[tex]h=4.4 km = 4400 m[/tex] (height)
So the volume is
[tex]V=\pi R^2 h = \pi (88,000)^2 (4400)=1.07\cdot 10^{14} m^3[/tex]
The density is
[tex]\rho = 1.3 kg/m^3[/tex]
So the mass is
[tex]M=\rho V=(1.3)(1.07\cdot 10^{14})=1.39\cdot 10^{14} kg[/tex]
Therefore, the energy is
[tex]E=\frac{1}{4}(1.39\cdot 10^{14})(27.8)^2=2.7\cdot 10^{16} J[/tex]
a spring stretches by 0.12 m when some apples weighing 3.2 N are supported from it. What is the Spring Constant?
Answer:
Fa==kx
ma=-kx
(3.2)(9.8)=-k(0.12)
k=27 N/M
The spring constant is 27 N/M.
What is Force?A force is defined as an effect that can change the motion of an object so that an object with mass can change its velocity, i.e., accelerate. Force can also be described simply as a push or pull. A force has both magnitude and direction which makes it a vector quantity.
Force is expressed as Mass times acceleration, i.e. F=ma. The SI unit of force is Newton (N).
F = -kx.
This proportional constant k is called the spring constant which is a measure of the spring's stiffness.
So, when we put both the equation together, we get
ma = -kx
Given, (3.2)(9.8)=-k(0.12)
k=27 N/M
Thus, the spring constant is 27 N/M.
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What is another term for a Lewis structure diagram?
Proton-electron ratio
Valence bond diagram
Bond pair visual
Electron-dot diagram
Final answer:
Another term for a Lewis structure diagram is an 'electron-dot diagram,' which represents the valence electrons of an atom as dots around the element's symbol and is used to visualize the bonding and non-bonding electrons in molecules.
Explanation:
Another term for a Lewis structure diagram is an electron-dot diagram. A Lewis structure diagram is a representation that shows the valence electrons of an atom as dots around the symbol of the element. The dots represent the number of valence electrons present in the atom and are arranged around the chemical symbol in a specific manner with a maximum of two dots on one side. For instance, the Lewis diagram for hydrogen would consist of the symbol 'H' with one dot next to it, representing its single valence electron.
The Lewis diagram is also referred to as a Lewis dot diagram and is used to visualize the bonding between atoms as well as non-bonding valence electrons. When atoms bond, the shared electrons are represented by lines, and lone pairs are depicted by dots surrounding the atoms. These diagrams help in predicting the shape of molecules and the arrangement of atoms.
what is the resistance of a 20.0 meter long tungsten rod with a cross sectional area of 1.00 times 10^-4 meter^2 at 20C
Answer:
[tex]0.0112 \Omega[/tex]
Explanation:
The resistance of an object tells us how much the object opposes to the flow of current through it.
The resistance of a conductor is given by the formula
[tex]R=\frac{\rho L}{A}[/tex]
where
[tex]\rho[/tex] is the resistivity of the material
L is the length of the conductor
A is the cross-sectional area
For the tungsten rod in this problem, we have:
L = 20.0 m is the length
[tex]A=1.00\cdot 10^{-4}m^2[/tex] is the cross-sectional area
[tex]\rho=5.6\cdot 10^{-8} \Omega \cdot m[/tex] is the resistivity of tungsten at 20C
Substituting into the formula, we find the resistance of the tungsten rod:
[tex]R=\frac{(5.6\cdot 10^{-8})(20.0)}{1.00\cdot 10^{-4}}=0.0112 \Omega[/tex]
What is the relationship between wavelength and the amount of energy the wave carries?
Answer:
Energy is inversely proportional to wavelength.
Explanation:
The amount of energy, E, a wave carries is given as:
E = hf
where h = Planck's constant and f = frequency of the wave
Frequency and wavelength are related by the equation:
c = λf
=> f = c/λ
where λ = wavelength
Therefore, energy is:
E = hc/λ
This shows that energy is inversely proportional to wavelength. As wavelength increase, energy decreases and vice versa.
The wave property that is related to the height of a wave is the
Answer:
Amplitude
Explanation:
The amplitude is maximum height a wave is measured from its rest position.
What kinds of information does the ALMA radio telescope provide?
Answer:
Atacama Large Millimeter/Submillimeter Array (ALMA) Observatory's primary goal is to provide a radio telescope array that will allow scientists to observe and image galaxies out to the edge of the universe, and stars and planets in their formative stages with unprecedented clarity.
Explanation:
Answer:
- the location of dust and gases in space
- places where stars will be born
Explanation:
got it right on edmentum.
what is an example of friction
A) slipping on a patch of ice
B) dropping a book
C) diving into a swimming pool
D) wind blowing against you on a walk
Answer: slipping on a patch of ice (A)
Explanation: there is direct contact when you slip on a patch of ice: your body, and the ice. all of the other answers are either non contact, or it is not solid to solid (wind, water). hope that makes sense :)
In the diagram, q1 = +0.250 mC, q2 = -0.180 mC, and q3 = +0.400 mC. the net force on q2 is zero. how far is q2 from q3? (make sure you know the direction of each force!) (hint: milli means 10^-3.) (unit = m)
Answer:
1.250
Explanation:
A carpenter has a mix of both iron nails and plastic nails in a jar. For a job, he needs only the iron nails. What physical properties could help him separate the nails?
Answer:
Magnetism
Explanation:
The carpenter can separate the iron nails from the plastic nails using a magnet. The iron nails have magnetic properties therefore they would be attracted to the magnet living only the plastic nails. This process is known as magnetic separation because it is based on the physical properties of the mixed components separating a mixture of components containing magnetic and non magnetic materials.
why does a diverging lens never produce a real image?
Do baking bread release or absorb energy
Help ASAP
Answer question 3 please!!!
Answer:
the answer is ture
Explanation:
because the energy substances must absorb in order to change from liquid to gas
Momentum can be defined as "mass inmotion." All objects have mass; so if anobject is moving, then it has momentum - ithas its mass in motion. The amount ofmomentum which an object has is dependentupon two variables: how much stuff is movingand how fast the stuff is moving. Momentum depends upon the variablesmass and velocity. In terms of an equation, the momentum of an objectis equal to the mass of the object times the velocity of the object. T/F
Answer:
T
Explanation:
momentum=mass×velocity
The momentum of an object is equal to the mass of the object times the velocity of the object which is true.
What is momentum?In Mechanics, momentum is calculated as the combination of an object's weight and speed. It has both a magnitude and a direction, making it a vector quantity. If an entity has weight m and speed v, then its momentum is given by,
p = mv
Where 'p' is the momentum, 'm' is the mass, and 'v' is the velocity.
Mass in motion is a definition of momentum. All things have mass, thus when something moves, it has momentum because its mass is in motion. The amount of momentum an object possesses depends on two factors: how much and how quickly the material is moving.
It is correct to say that an object's momentum is equal to its mass times its velocity.
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Use the drop-down menus to complete the sentences
Athin wire has resistance than a thick wire,
A short wire has resistance than a long wire
A warm wire has resistance than a cool wire,
Done
Answer:
A thin wire has a higher resistance than a thick wire
A short wire has a lower resistance than a long wire
A warm wire has a higher resistance than a cool wire
Explanation:
Here we have the formula for resistance by diameter given as follows
[tex]R = \frac{4 \times \rho \times l}{\pi } \times \frac{1}{d^2}[/tex]
Where:
R = Resistance
ρ = Resistivity of the wire
l = Length of the wire
d = Diameter of the wire
a. Therefore, since resistance is inversely proportional to diameter of the wire, a thin wire
A thin wire produces a higher resistance value than a thicker wire with larger diameter, d
b. Also as resistance is directly proportional to the length of the wire, a long wire has a higher resistance value than a short wire
c. The formula for resistance of a wire with temperature is as follows;
[tex]R_T = R_0 \times [1 + \alpha \times (T - T_{20})][/tex]
Where:
R₀ = Copper resistance at 20°
[tex]R_T[/tex] = Copper resistance at temperature T
T = Copper conductor temperature
T₂₀ = 20°
α = Copper coefficient of resistivity
Therefore, as the temperature increase, the resistance increases.
Answer:
thin wire has
✔ more
resistance than a thick wire.
A short wire has
✔ less
resistance than a long wire.
A warm wire has
✔ more
resistance than a cool wire.
Explanation:
. Suppose you have a device that extracts energy from ocean breakers in direct proportion to their intensity. If the device produces 10.0 kW of power on a day when the breakers are 1.20 m high, how much will it produce when they are 0.600 m high?
Answer:
4.988kW
Explanation:
According to the question, energy E extracted from the ocean breaker is directly proportional to the intensity I. It can be expressed mathematically as E ∝ I
E = kI where k is the constant of proportionality.
From the formula; k = E/I
This shows that increase in energy extracted will lead to increase in its intensity and vice versa.
If the device produces 10.0 kW of power on a day when the breakers are 1.20 m high
E = 10kW and I = 1.20m
k = 10/1.20
k = 8.33kW/m
To know how much energy E that will be produced when they are 0.600 m high, we will use the same formula
k = E/I where;
k = 8.33kW/m
I = 0.600m
E = kI
E = 8.33 × 0.6
E = 4.998kW
The device will produce energy of 4.998kW when they are 0.600m high.
Answer:
It will produce 2.5 Kw at 0.6m high
Explanation:
We are given;
Initial Power output of device; P_i = 10 Kw
Initial amplitude; A_i = 1.2m
Final Amplitude; A_f = 0.6m
We know that power is directly proportional to energy because
P = Energy(work done)/time taken
Thus; P ∝ E - - - - (eq1)
Now,from the question, we are told that Energy is proportional to the intensity. Thus;
E ∝ I - - - - (eq2)
where I is intensity
Now, from formula of Intensity, which is; I = (1/2)(ρ²•β²•ω²•A²)
We can see that I is directly proportional to square of Amplitude A²
Thus, I ∝ A² - - - - (eq3)
Combining eq 1,2 and 3,we can deduce that;
P ∝ E ∝ I ∝ A²
Thus, P ∝ A²
Now, let's set up the proportion as;
P_i/P_f = A_i²/A_f²
Since we are looking for final power, let us make P_f the subject.
So,
P_f = (P_i•A_f²)/A_i²
Plugging in the relevant values to obtain ;
P_f = (10 x 0.6²)/1.2² = 2.5 Kw
When light bends or changes direction what is happening
Answer:
When light travels from air into water, it slows down, causing it to change direction slightly. This change of direction is called refraction. When light enters a more dense substance (higher refractive index), it 'bends' more towards the normal line
The Tour de France is the biggest bicycle race in the world. The race lasts for three weeks and is one of the biggest sporting events of the year. At the end of each day of racing they give to the certain riders FOUR different colored jerseys. What are the four different colored jerseys AND what does it mean to the rider that gets to wear it the next day?
Answer:
Yellow, green, polka dot and white jerseys
Explanation:
Tour de France is the biggest bicycle race in the world held at France over a period of 23 days. At the end of each day of racing they give to the certain riders FOUR different colored jerseys:
The yellow jersey is given to the overall winner at each stage, this shows the rider who was the best in the previous stage.The green jersey is given to the best sprinter of each stage, The polka dot jersey is given to the rider who first reach the crest of designated hills and mountains at each stage.The white jersey is given to the fastest rider at each stage under 25 years at the beginning of the racing year.At the end of the competition, the total points are counted and the different jerseys are given to the overall winners.
where would a new neuron come from
Gears can be used to change the direction of a motor output from clock wise to counter clockwise
True or false
Answer:
True
Explanation:
This can be done when the output gear is rotating in a counterclockwise direction. The initial direction of the clockwise gear changes when it comes in contact with the counter clockwise rotating gear. This will thus cause the motor to change its direction due to the counter clockwise rotating gear.
If the velocity of a pitched ball has a magnitude of 47.0 m/s and the batted ball's velocity is 50.5 m/s in the opposite direction, find the magnitude of the change in momentum of the ball and of the impulse applied to it by the bat.
Answer:
The magnitude of change in momentum of the ball is [tex]97.5 m[/tex] and impulse is also [tex]97.5 m[/tex]
Explanation:
Given:
Velocity of a pitched ball [tex]v _{i} = 47[/tex] [tex]\frac{m}{s}[/tex]
Velocity of ball after impact [tex]v_{f} = -50.5[/tex] [tex]\frac{m}{s}[/tex]
From the formula of change in momentum,
[tex]\Delta P = m (v_{f} -v_{i} )[/tex]
Here mass is not given in question,
Mass of ball is [tex]m[/tex]
Change in momentum is given by,
[tex]\Delta P = m (-50.5 -47)[/tex]
[tex]\Delta P = -97.5 m[/tex]
Magnitude of change in momentum is
[tex]\Delta P = 97.5 m[/tex]
And impulse is given by
[tex]J = \Delta P[/tex]
[tex]J = -97.5 m[/tex]
So impulse and
Therefore, the magnitude of change in momentum of the ball is [tex]97.5 m[/tex] and impulse is also [tex]-97.5 m[/tex]
Is the following sentence true or false? The three main types of
mechanical waves are water waves, longitudinal waves, and surface
waves.
Answer:
False
Explanation:
the three types are transverse, longitude, and boundary
Which graph best represents the relationship between the electric current and the rate at which a magnet is turning inside an electric generator?
Answer:
The second one.
Explanation:
The relationship between the electric current and the rate at which a magnet is turning inside an electric generator is linear in nature.
What is electric generator?A dynamo is an electric machine that converts mechanical energy into electrical energy. Steam turbines, gas turbines, and wind turbines typically supply mechanical energy to electric generators. Electrical generators supply nearly all of the power needed for electric power grids.
An electric motor converts electrical energy to mechanical energy in the opposite direction. Many similarities exist between motors and generators. However, in this article, we will concentrate primarily on electric generators and how they convert mechanical energy to electrical energy.
Hence, the relationship between the electric current and the rate at which a magnet is turning inside an electric generator is linear in nature.
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If you push down the plunger of a bicycle pump the vhamber's volume is decreased. When that happens pressure in the chamber increases and the air then rushes out the pump and into your flat tire. What gas law does this represent?
Answer:
Boyle's Law
Explanation:
Robert Boyle in his experiment explained the relationship between the volume and the pressure of a gas. In his experiments, he discovered that the volume of a gas is inversely proportional to the pressure at constant temperature. This implies that as the volume of the gas increase, the pressure decreases and as the volume of the gas decrease, the pressure will increase.
Now applying this concenpt to the the plunger of a bicycle pump, you will discover that as the pressure of in the plunger increase, the volume of air inside the chamber is decreasing as it is send out to pump the flat tyre. This clearly indicates inverse proportionality between pressure and volume as explained by Boyle's law.
Therefore, the plunger of a bicycle pump clearly indicates Boyle's law in action.
The operation of a bicycle pump illustrates Boyle's Law. This law states that in a closed system at constant temperature, the volume and pressure of a gas are inversely proportional - as one increases, the other decreases.
Explanation:The situation you described is an application of Boyle's Law, a concept in physics. Boyle's Law states that the pressure and volume of a gas have an inverse relationship when held at a constant temperature. This means that as the volume of gas decreases, like when you push down the plunger of a bicycle pump, the pressure increases.
When the plunger is pushed down, the volume inside the pump decreases, thereby increasing the pressure. This high-pressure air then moves from an area of high pressure (inside the pump) to an area of low pressure (the flat tire), resulting in air being pumped into the tire.
A practical example aiding understanding is a deflated tire. As we start pumping air into it, its volume first increases with not much increase in pressure. However, once the tire is filled to a point where the walls resist further expansion, pressure increases as more air is pumped in. Therefore, Boyle's Law explains the mechanics of a bicycle pump and similar systems pretty well.
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my teacher didnt explain this well and im lost
Explanation:
(a) The given figure is a convex lens.
(b) In this figure, the object is placed between F and optical center of a lens. Convex lens is a converging lens. It converges the beam of light falling on it after reflection. The image is formed on the same side of the lens as the object.
The formed image is enlarged and it is virtual and erect.
(i) Type : virtual
(ii) Orientation : upright
(iii) Size : Enlarged
Ice floats in water at 0°C. Why is this an example of physical equilibrium? a)The system is closed; nothing leaves the system. b)No new substances form when the water molecules change state. c)The forward and reverse processes occur at different rates.
Answer: Option (b) is the correct answer.
Explanation:
Physical equilibrium is defined as a system in which there will occur no change in the physical state of substance. For example, at zero degree celsius water is present in both liquid and solid state as follows.
[tex]H_{2}O(l) \rightleftharpoons H_{2}O(s)[/tex]
For a system to be present in physical equilibrium is as follows.
The system must be a closed system.
It should be dynamic in nature.
There will occur no change in measurable property along with change in time.
Thus, we can conclude that ice floats in water at [tex]0^{o}C[/tex] this an example of physical equilibrium because no new substances form when the water molecules change state.
During a 78-ms interval, a change in the current in a primary coil occurs. This change leads to the appearance of a 4.1-mA current in a nearby secondary coil. The secondary coil is part of a circuit in which the resistance is 12 Ω. The mutual inductance between the two coils is 3.2 mH. What is the change in the primary current?
Answer:
1.2 A
Explanation:
We are given that
Time, dt=78 ms=[tex]78\times 10^{-3}s[/tex]
[tex]1 ms=10^{-3} s[/tex]
[tex]I_s=4.1mA=4.1\times 10^{-3} A[/tex]
[tex]1 mA=10^{-3}A[/tex]
[tex]R=12\Omega[/tex]
[tex]M=3.2mH=3.2\times 10^{-3} H[/tex]
We have to find the change in the primary current.
[tex]V_s=I_sR=4.1\times 10^{-3}\times 12=49.2\times 10^{-3} V[/tex]
[tex]V_s=M\frac{dI}{dt}[/tex]
[tex]dI=\frac{V_sdt}{M}=\frac{49.2\times 10^{-3}\times 78\times 10^{-3}}{3.2\times 10^{-3}}[/tex]
[tex]dI=1.2 A[/tex]
Water is traveling into what sphere during infiltration?