Answer:
32%
Explanation:
For a heat engine, efficiency is work out divided by heat in:
η = Wₒ / Qᵢ
Since energy is balanced, heat in is the sum of work out and heat out:
Qᵢ = Wₒ + Qₒ
Therefore:
η = Wₒ / (Wₒ + Qₒ)
Given Wₒ = 710 J and Qₒ = 1480 J:
η = 710 / (710 + 1480)
η = 0.32
The thermal efficiency is 32%.
an object at rest requires a force of 15 newtons to set it into motion. The force is greater than which force?
Answer:
Friction
Explanation:
Friction is a force that opposes the movement of an object's relative motion. Friction always goes against the attempted movement of the object when they are in contact. In other words, it is a force that prevents objects from sliding past each other.
The answer is friction.
I took the test and got it right.
In young’s experiment how must waves be vibrating to for interference to occur
A. Out of line
B. In line
C. In phase
D. Out of ohase
In phase for constructive interference and out of phase for destructive
A yo-yo is swung around the head of a person in a horizontal circle. What provides the
centripetal force on the yo-yo?
Answer:
There is a net force towards the center of the circle that causes the yo-yo to seek the center.
Circular Motion Qualities:
-Constant speed
-Accelerating
-Velocity is changing constantly.
Centripetal acceleration perpendicular to the motion causes the object to change direction
a_c=v^2/r
Tangential acceleration in the direction of the motion causes and increase or decrease in speed.
Tension in the string towards the center provides the centripetal force in a a yo-yo swinging around a person's head.
Centripetal force is the force that keeps an object moving in a circular path. In the case of a yo-yo swung around a person's head, the centripetal force is provided by the tension in the string acting towards the center of the circle. This force allows the yo-yo to maintain its circular motion.
which best describes how the sun rotates?
Answer:
The sun rotates more slowly at its poles.
Answer:
The sun rotates more slowly at its poles.
can someone pls answer number 8 for me pls
Answer:
1.33 m
Explanation:
Tom weighs 600 N and is 2 meters from the pivot. So his moment is:
τ = Fr
τ = (600 N) (2 m)
τ = 1200 Nm
To balance the see-saw, Jeremy must create an equal and opposite moment.
τ = Fr
1200 Nm = (900 N) r
r = 1.33 m
So Jeremy must sit 1.33 m from the pivot on the other side.
Which formula is used to calculate the mass of an object if the force and acceleration are known?
Answer: Multiply Both Volume And Density
Explanation: Multiply the volume and density together. Multiply your two numbers together, and you'll know the mass of your object.Keep track of the units as you do this, and you'll see that you end up with units of mass (kilograms or grams).
For this case we have by definition, Newton's second law of motion states that the force is directly proportional to the mass and to the acceleration of a body. That is to say:
[tex]F = m * a[/tex]
Where:
F: It's the strength
m: It's the mass
a: It's the acceleration
ANswer:
[tex]F = m * a[/tex]
A 2.5-kg rock is dropped
Answer:
Okay it dropped now what..........................................
Explanation:
Is the rock okay I’m concerned
Kinetic energy is measured in units of
If the mass has units of kilograms and the velocity of meters per second, the kinetic energy has units of kilograms-meters squared per second squared.
Kinetic energy is usually measured in units of Joules (J); one Joule is equal to 1 kg m2 / s2.
Kinetic energy is the energy of motion and is measured in Joules (J), which equates to kg · m²/s² in SI units. This is because it represents the same physical property as work and energy in physics.
Explanation:Kinetic energy is measured in units of joules (J), which are also the units for work and energy. This is because kinetic energy, the energy of motion, is related to the work done on an object and is a form of energy. The joule is defined as 1 kg · m²/s² in standard SI units, meaning it represents the amount of kinetic energy held by an object with a mass of 2 kilograms, moving with a velocity of 1 meter per second.
Historically, energy was measured in units of calories, but the SI unit of heat, work, and energy is the joule. One Joule is equivalent to 1 kg m²/s², which is also called 1 newton-meter. To standardize its definition, 1 calorie has been set to equal 4.184 joules.
The kinetic energy of an object can be calculated by the equation KE = 1/2mv², where 'm' is the mass of the object and 'v' is its velocity. This equation demonstrates that kinetic energy is proportional to the square of an object's speed, highlighting the relationship between energy, mass, and motion.
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What basic parts does a circuit need?
Answer:
Every electric circuit, regardless of where it is or how large or small it is, has four basic parts: an energy source (AC or DC), a conductor (wire), an electrical load (device), and at least one controller (switch).
Explanation:
Cell (battery)
Wires
Bulb or motor
How does water affect metamorphic processes?
Answer:
When the temperature and pressure of a rock undergoing metamorphism changes. the composition of water allows materials to move more easily, the presence of fluids makes metamorphism more easy.he fluid changes also.
Explanation:
Answer:
It can have elevated concentrations of dissolved substances
Explanation:
Cause I happened to know
Explain how the sun's position in the sky affects the length of shadows
ps.multiple sentences, please
A shadow forms on the side of an object that faces away from the sun. The length of shadows changes as Earth rotates. In the morning, the sun is low in the eastern sky and shadows are long. As time passes in the morning, the sun seems to move higher in the sky.
The size of the object changes with change in the position of the light source.The length of the shadow of the object decreases as the sun position changes from down to top in the sky.
SunlightSunlight has the sun rays. This rays travel to the earth. When the sun rays reach to earth they hit the object comes in his way. If the sun rays hit the opaque body ( a body that absorb some light when light fall on it) the light can not pass through them and the shadow appears.
What is the affect pf sun's position on the length of shadows?The shape of a object determine the shape of the shadow made by him but the size of the object does not depends on the size of the object.
The size of the object changes with change in the position of the light source.The shadow appears in the opposite direction from where the sunlight falls on body.
At the outdoor, when there is sun in the sky, the size of the shadow is different at different sun position on the sky.
At the time of morning the sun is in the east direction low level at sky. At this position the sun rays passes through the objects vertically. It results in the long shadow of the object in the west direction.At the time of noon the sun is at top of the sky. The sun rays fall on a object vertically. The shadow made by the object is smaller or nothing as the opposite surface is grounded. Thus in the noon time the shadow length is smaller.At the time of evening the sun is again down in the sky. The sun rays falls vertically, Hence the shadows made by the object is longer and in the east direction.Hence the length of the shadow of the object decreases as the sun position changes from down to top in the sky.
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Which part of an atom has most of its mass? A. electrons B. neutrons C. nucleus D. protons
The nucleus has most of the atomic mass in an atom. The nucleus is made up of protons and neutrons.
The nucleus of an atom is located at its center and contains most of its mass. The correct answer is C.
It is composed of protons and neutrons, which are collectively known as nucleons. Protons have a positive charge, while neutrons have no charge. Electrons, on the other hand, are negatively charged particles that orbit the nucleus in energy levels or shells.
Although electrons are much lighter than protons and neutrons, they occupy a larger volume around the nucleus due to their lower mass. The mass of an electron is approximately 1/1836th the mass of a proton or neutron.
Therefore, when considering the total mass of an atom, the mass of the electrons is relatively insignificant compared to the mass of the nucleus, which is primarily composed of protons and neutrons. The correct answer is C.
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Which statement does Einstein's theory promote about space and time?
O
O
O
O
Time, space, and the speed of light depend on reference frames.
Time and space depend on reference frames, but the speed of light does not.
The speeds of light and space depend on reference frames, but time does not.
The speeds of light and time depend on reference frames, but space does not.
Answer:
2nd statement would be the right answer
Answer: Time and space depend on reference frames, but the speed of light does not.
Explanation: According to Einstein Space and Time are directly related as the way we sense them, in his words space and time is like a fabric in which we cannot affect one without affecting the other as we interact with it, time can be stretched and squeezed depending on your inertial frame of reference (constant speed and mass). However light can travel thru the fabric of space and time and it does not get affected by any reference keeping always the same speed.
Which statement best describes the relationship between work and energy?
Work is the mechanism by which energy is transferred or changed in an object, described by the work-energy theorem. Work done on an object equals the change in kinetic energy, demonstrating the intimate relationship between work and energy, and can be calculated using the formula W = Fd*cos(θ). Energy is defined as the ability to do work, connecting it intrinsically to the concept of work.
The Relationship Between Work and Energy
The statement that best describes the relationship between work and energy is that work is the means through which energy is transferred or transformed from one body or system to another. When work is done on an object by applying a force over a distance, the energy of the object changes. This can be in the form of kinetic energy, which is the energy of motion, or potential energy, which is stored energy due to position or composition. The work done on an object is equal to the change in kinetic energy of the object, which is a concept known as the work-energy theorem.
In mechanical terms, work (W) can be expressed as the product of the force (F) in the direction of displacement times the distance (d) the object moves while the force is applied: W = Fd*cos(θ), where θ is the angle between the force vector and the displacement vector. Work and energy are measurable in the same units, Joules (J), underscoring their close relationship.
In essence, energy is defined as the capacity to do work. Therefore, understanding work is essential to grasping how energy is transferred or conserved within a system. In terms of conservation, the first law of thermodynamics states that the total internal energy change in a system is equal to the heat added to the system minus the work the system performs. Thus, the concept of work serves as a fundamental bridge between force interactions and energy changes in physical systems.
Plants make energy. Some of it they use to preform the necessary functions of living. What do they do with the excess energy?
Answer:
They can use it for when they are dormant in the winter or to grow more sources for storing and creating energy, or they store the energy (this energy would be considered stored energy).
Please tell me the order the answers go. Best and most correct answer gets Brainliest.
See the attached picture:
What is pitch related to in terms of sound? Does it affect the speed? If so, how?
Answer:
Pitch is the listener's perception of the frequency of sound, but it does affect the speed.
Explanation:
Depending on the frequency at which the sound waves that produce them vibrate, sounds have a higher or lower pitch.
What is the pitch of the sound?A low frequency, such as 55 Hz, is heard as a low pitch and a high frequency, such as 880 hertz [Hz; cycles per second], as a high pitch.
In frequency, hertz units are used. The pitch of a sound wave increases with the speed of oscillation.
Pitch and sound frequency are connected. The frequency increases as the pitch rise. The length of the vibrating item affects the frequency and pitch of the vibration.
For instance, a shorter string vibrates more quickly than a longer string, producing a greater frequency and pitch.
Therefore, the pitch is related to in terms of sound The higher the pitch of the sound, the higher the frequency, and vice versa, hence they are directly correlated.
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What is another name for the surface of the sun?
Answer: Chromosphere hope this helps :)
A sphere is charged with electrons to
−7 × 10−6 C.
How many electrons make up this charge?
The elemental charge is 1.6 × 10−19 C.
Answer:
[tex]4.38\cdot 10^{13}[/tex] electrons
Explanation:
The net charge on the sphere is equal to:
[tex]Q=-7\cdot 10^{-6}C[/tex]
This charge is made up of N electrons. Each electron carries a charge of
[tex]q=-1.6\cdot 10^{-19}C[/tex]
So the total charge is just the number of electrons times the charge of each electron:
[tex]Q=Nq[/tex]
And solving the equation for N, we find the number of electrons:
[tex]N=\frac{Q}{q}=\frac{-7\cdot 10^{-6}C}{-1.6\cdot 10^{-19} C}=4.38\cdot 10^{13}[/tex]
An atomic nucleus is composed of A) protons. B) protons and neutrons. C) protons and electrons. D) protons, neutrons, and electrons.
Answer:
B
Explanation:
The nucleus is made up of protons and neutrons, and electrons float around the neucleus in the electron cloud.
The atomic nucleus is made up of two particles that are protons and neutrons.
Answer: Option B.
Explanation:
The atom has the core part as the nucleus in the center part of the atom. The nucleus consists of two particles. These are namely, protons and neutrons.
Proton contains a positive charge but whereas the neutron does not have any charges; therefore, the nucleus acquires the positive charge of the proton. Both of them together constitute the atomic mass and the mass number.
Application of a biot-savart law
can be used to determines the expression for magnetic field strength of a current element
The Biot-Savart law is important for calculating magnetic fields from current loops but can be complex and time-consuming. It requires the use of cross-products and integration along the current-carrying wire. When symmetry exists, Ampère's law might offer a simpler solution.
Explanation:One advantage of the Biot-Savart law is its ability to calculate the magnetic field produced by any current loop configuration, offering versatility in physics problems. A disadvantage is that it can be complex and time-consuming, particularly when dealing with intricate geometries where symmetry is lacking. When approaching a problem, if there is symmetry, one may consider Ampère's law as an alternative for simplifying calculations especially when a clear path of integration is present.
To apply the Biot-Savart law, it is necessary to define the current element dI and unit vector r, calculate their cross-product, and integrate this across the length of the current-carrying wire. This allows determination of the magnetic field's magnitude and direction. In specific setups, such as calculating the magnetic field of an infinite wire, the desired precision dictates certain assumptions like treating finite segments as effectively infinite when they align closely with the wire's length.
Overall, the Biot-Savart law provides a powerful tool for understanding how current-carrying wires influence the magnetic fields in their vicinity, which is a foundational concept in electromagnetism.
Dimension formula of under root LC
The square root of LC has the dimension of time. Its reciprocal is frequency.
The dimension of under root LC is calculated by taking square root of the multiplication of the dimensions of L (Inductance) and C (Capacitance). Using the dimensions of L as [M][L][T]-2 [I]-2 and C as [M]-1 [L]-2 [T]4 [I]2, the dimension of under root LC is [M]-1/2 [L]-1 [T]2 [I].
Explanation:The question asks for the dimension of under root LC where L is Inductance and C is Capacitance. Both of these are primary physical quantities where the dimension of L is [M][L][T]-2 [I]-2 and the dimension of C is [M]-1 [L]-2 [T]4 [I]2. To find the dimension for under root LC, we can square root the multiplication of the dimensions of L and C, which means that the dimension of under root LC is [M]-1/2 [L]-1 [T]2 [I].
Here, M stands for mass, L for length, T for Time, and I for Current.
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In both the U.S. House of Representatives and U.S. Senate, which of the selections below is elected by the party with the most members of that chamber?
Select one:
A. Party Conference Committee Chair
B. Majority Leader
C. Minority Whip
D. Majority Whip
Answer In Letter form please
I believe the answer is B
Answer:
B
Explanation:
Because its just b trust me
Your backpack has a mass of 8 kg. You drop it from a height of 1.3m. How much work is done by gravity as the backpack falls?
A. -102 J
B. -10.4 J
C. 102 J
D. 10.4 J
Answer:
The answer is C.
Explanation:
I guessed and it was right
Answer:
Work done by the gravity, W = 102 J
Explanation:
It is given that,
Mass of the backpack, m = 8 kg
It is dropped from the height of, h = 1.3 m
We have to find the work done by the gravity as the back pack fall. Work done by the gravity is given by the product of force and distance covered by an object. Mathematically, it is given by :
W = F × d
∵ F = m g
⇒ W = mg h
[tex]W=8\ kg\times 9.8\ m/s^2\times 1.3\ m[/tex]
W = 101.92 Joules
or
W = 102 Joules
So, the work done by the gravity is 102 J. Hence, this is the required solution.
The case of Plessy v. Ferguson, which affirmed the system of segregation, was subsequently overturned in which of the cases listed below?
Select one:
A. Tinker v. Des Moines
B. District of Columbia v.Heller
C. Marbury v. Madison
D. Brown v. Board of Education
brown v board of ed
becasue i remember trust me
Answer: BROWN V BOARD OF EDUCATION.
…Court in the case of Plessy v. Ferguson established the doctrine of “separate but equal.”…. Jim Crow law. …1954 the Supreme Court reversed Plessy in Brown v. Board of Education of Topeka. It declared segregation in public schools unconstitutional, and, by extension, that ruling was applied to other public facilities.
Explanation:
what are most elements on the periodic table?
Answer:
Metals, nonmetals and metalloids.
Explanation:
Answer:
Is metals, Non metals, Metalloids
The periodic table on the left separates elements into three groups : the metals (green in the table), nonmetal (orange), and metalloids (blue) . most elements are metal. they are usually shiny,very dense , and only melt at high temperatures .
As object moving east, and it’s velocity changes from 65 m/s to 2/5ms in 10 seconds. Which describes acceleration?
Answer:
-4.0 m/s^2
Explanation:
Acceleration is defined as the rate of change in velocity:
[tex]a=\frac{v-u}{t}[/tex]
where
v is the final velocity
u is the final velocity
t is the time elapsed
For the object in this problem,
u = 65 m/s
v = 25 m/s
t = 10 s
So the acceleration is
[tex]a=\frac{25 m/s-65 m/s}{10 s}=-4.0 m/s^2[/tex]
The negative sign tells that the acceleration is opposite (=west) to the velocity (which is towards east).
Answer:
A
Explanation:
I’m gay
Which best describes a material with a low index of refraction (near 1)?
A. It causes light to refract significantly.
B. The speed of light stays constant.
C. Is causes light to slow and refract very little.
D. Light is mostly reflected at a value near 1.
it causes light to slow and refract very little
Answer:
it causes light to slow and refract very little
Explanation:
its on my test
A car headed north at 15m/s experiences an acceleration of 2.5 m/s2 for 3 s. What is the final velocity of the car
Answer:
= 22.5 m/s
Explanation:
The acceleration of a moving body is calculated by the formula;
a = (v-u)/t
Where; a is the acceleration of the body
v is the final velocity of the body
u is the initial velocity of the body and
t is the time taken
In this case;
u = 15 m/s
a = 2.5 m/s²
t = 3 seconds
2.5 m/s² = ( v- 15 m/s)/3 seconds
2.5 × 3 = v - 15
7.5 = v - 15
v = 7.5 + 15
= 22.5 m/s
Entropy can only be decreased in a system if ...
a)heat is removed
b)disorder is increased
c)energy is added
d)efficiency is zero
ANSWER FAST PLEASEEEEEE
Answer:
a)heat is removed
Explanation:
Entropy is the a stare of randomness or disorderliness of the particles of a system.
The entropic level of a system depends on temperature and physical state of matter.
With increasing temperature, the randomness of the particles of a system increases. When heat is removed from a system, the entropy reduces and orderliness is approached. For example, the entropy of steam would decrease if we place it in a refrigerator. In the refrigerator, work is done on the steam to remove the heat and reduce the temperature. The vapour moves from gas to liquid and then to a more ordered ice.
When disorder increases, entropy increases also.
When we add more energy to a system, it causes a rise in randomness.
Answer:
it is not a) heat is removed
Explanation:
just got it wrong because of the previous reply :(