What is the efficiency of an engine that does 20 J of work and exhausts 80 J
of heat while taking in 100 J of heat? Use e=
Wtotal/ Qin

A. 80%
B. 10%
C. 20%
D. 25%

(PLEASE HELP NEED ANSWER ASAP)

Explanation:

The situation described here is parabolic movement. However, as we are told that the rock was projected upward from the surface, we will only use the equations related to the Y axis.

In this sense, the movement equations in the Y axis are:

[tex]y-y_{o}=V_{o}.t+\frac{1}{2}g.t^{2}[/tex]    (1)

[tex]V=V_{o}-g.t[/tex]    (2)

Where:

[tex]y[/tex]  is the rock's final position

[tex]y_{o}=0[/tex]  is the rock's initial position

[tex]V_{o}=30\frac{m}{s}[/tex] is the rock's initial velocity

[tex]V[/tex] is the final velocity

[tex]t[/tex] is the time the parabolic movement lasts

[tex]g=1.62\frac{m}{s^{2}}[/tex]  is the acceleration due to gravity at the surface of the moon

As we know [tex]y_{o}=0[/tex] , equation (2) is rewritten as:

[tex]y=V_{o}.t+\frac{1}{2}g.t^{2}[/tex]    (3)

On the other hand, the maximum height  is accomplished when [tex]V=0[/tex]:

[tex]V=V_{o}-g.t=0[/tex]    (4)

[tex]V_{o}-g.t=0[/tex]    

[tex]V_{o}=g.t[/tex]    (5)

Finding [tex]t[/tex]:

[tex]t=\frac{V_{o}}{g}[/tex]    (6)

Substituting (6) in (3):

[tex]y=V_{o}(\frac{V_{o}}{g})+\frac{1}{2}g(\frac{V_{o}}{g})^{2}[/tex]    (7)

[tex]y_{max}=\frac{{V_{o}}^{2}}{2g}[/tex]    (8)  Now we can calculate the maximum height of the rock

[tex]y_{max}=\frac{{(30m/s)}^{2}}{(2)(1.62m/s^{2})}[/tex]   (9)

Finally:

[tex]y_{max}=277.777m[/tex]  

Answer:

An MRI scanner applies a very strong magnetic field

Explanation:

Magnetic resonance imaging (MRI) uses a superconducting magnet to create a strong magnetic field, causing hydrogen nuclei in the body to emit signals when subjected to a radio frequency current. These signals are interpreted by a computer to form detailed images of internal structures that differentiate between tissue types and provide information about organ function and health conditions.

How Do MRIs Physically Work?

MRI, or magnetic resonance imaging, is a technique that uses a combination of strong magnetic fields and radio waves to generate detailed images of the inside of the body. The largest part of the MRI unit is a superconducting magnet that creates a consistent magnetic field, usually between 1 and 2 Tesla (T) in strength. Within this field, hydrogen nuclei, which are abundantly found within the water in soft tissues, align with the magnetic field.

When a radio frequency current is briefly activated, it creates a varying electromagnetic field that causes these hydrogen protons to absorb energy and move out of their initial aligned position. Upon deactivating the radio frequency field, the hydrogen protons release the absorbed energy and realign with the magnetic field, emitting electromagnetic signals in the process. The emitted signals are picked up by sensors within the MRI machine and subsequently interpreted by a computer to create a highly detailed image that differentiates tissues based on their density and composition.

This process allows medical professionals to gain invaluable information about structures within the body, from the shape of vertebral disks to the condition of brain tissue. The different responses of normal vs. non-normal tissues to slight changes in the magnetic field also provide insights into organ function and the presence of medical conditions such as tumours, strokes, and infections. MRI imaging is a powerful tool that can track ions across membranes, detail anatomical structures, and monitor organ function without exposure to ionizing radiation.

Answer:

molecule

Explanation:

Answer:

0.207x10^16 Joules!

Explanation:

Using Einstein's law of mass energy, we know that the energy of a matter is:

E = mc^2

where, m [kg] = mass

c [m/s] = speed of light

In this case:

m=23g = 0.023kg.

c = 3×10^8m/s (This is an aproximation)

Then:

E = mc^2 = (0.023kg)(3×10^8m/s)^2 = 0.207x10^16 Joules!

Answer:

Energy

Explanation:

Work is the transfer of energy

if the body is moving in a circle, then it moves with a centripetal acceleration and it is given by,

a=v^2/r

where, velocity(v)=30m/s

radius(r)=10 m

so a=30^2/10=90m/s^2

The body that is moving in a circle with a constant velocity of 30 m/s and radius of 10m has a centripetal acceleration of 90 m/s².

The student is inquiring about the acceleration of an object moving in a circle, specifically a body moving with a constant velocity in a circular path. This is a question of circular motion in Physics.

The acceleration of a body moving in a circle is called centripetal acceleration. It's directed towards the center of the circle. In Physics, the formula to calculate centripetal acceleration (ac) is:

ac = v^2/r

where:

In this scenario, the body is moving with a velocity (v) of 30 m/s and the radius (r) of the circle is 10 m. Using the above formula, the acceleration would be:

ac = 30^2 / 10 = 900 / 10 = 90 m/s²

The body has a centripetal acceleration of 90 m/s².

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Answer:

kjlp;;

Explanation:

Answer:

uranium gets used in bombs

Explanation:

Answer:

1.67 m/s

Explanation:

Momentum is conserved.

Initial momentum = final momentum

(30 kg) (10 m/s) + (35 kg) (-10 m/s) = (30 kg) v + (35 kg) (0 m/s)

300 - 350 = 30v

v = -5/3 m/s

Linus will move at 1.67 m/s in the direction opposite that he started.

Answer:

Common Physical Changes. Texture. Color. Temperature. Shape. Change of State.

Physical Properties. Luster. Malleability. Ability to be drawn into a thin wire. Density. Viscosity.

Common Chemical Changes. Change in Temperature. Change in Color. Noticeable Odor. Formation of a Precipitate.

Explanation:

Physical changes can be reversed usually by heating or cooling a substance, without any chemical bonds being broken.

Chemical changes CANNOT be reversed due too the chemicals being broken and forming something new.

Btw, I know you didn't need chemical change, but I put it in there anyway. Hope it helps.

Answer: if you are talking about the body then increased hormones as physical changes  with growing in sexual parts  and for guys increase in with muscles and growing in breast.

If it was of a change in physical properties. as of natural in universe then it would be melting, transition to different states of matter.

Explanation:

When everyone gets of age they grow and mature and these kind of changes happen

The reason for that would be of the change of strength, change of durability, changes to crystal form, textural change, shape, size, color, volume and density, These are some examples of physicals changes

Answer:

I believe it is A. Unbalanced.

Explanation:

Hope i helped you!

Unbalanced force causes an object to change its motion.

Answer: Option A

Explanation:

A force can be explained as push or a pull that has the tendency to change the velocity of a mass.

The force that makes any change in the movement of an object or body is known to be an unbalanced force. These forces are not equal and opposite. When an object is placed in a rest position and when unbalanced force acts on it, this will not make the object to move.

Example: Force applied against the ball.

The forces whose size is equal and opposite in their direction are known as balanced force. These forces will not make any change in motion of a body. When an object is placed in a rest position and when balance force acts on it, this will not make the object to move.

Example: Pushing against a wall.  

What two forces are required for generators and electric motors to work? “A” Electricity and magnetism.

In an electric motor, the energy transformation begins as “A” Electrical And becomes mechanical.

(a)  the two forces required for generators and electric motor to work is electricity and magnetism.

(b)  In an electric motor, the energy transformation begins as electrical and becomes mechanical.

According to Faraday's law, an emf is induced when there is a relative motion of a conductor placed in magnetic field.

Thus, the two forces required for generators and electric motor to work is electricity and magnetism.

Electric motor is a type of dynamo which converts electrical energy to mechanical energy.

Thus, In an electric motor, the energy transformation begins as electrical and becomes mechanical.

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Producing nuclear energy is far more environmentally friendly than burning fossil fuels. That is the main benefit.

The main risk is radiation. If the nuclear waste is not properly disposed of, it can leak radiation into the environment. Fortunately, this is not an issue since there are ways to deal with it. There is also the risk of a disaster like the Chernobyl incident, however that was mostly due to faulty reactor construction. However, reactors today are built to avoid such issues.

Nuclear energy is the energy released during nuclear fission or fusion, especially when used to generate electricity.

Advantages

Disadvantages

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An electromagnet is made from a coil of wire which acts as amagnet when an electric current passes through it. Often anelectromagnet is wrapped around a core of ferromagnetic material like steel, which enhances the magnetic field produced by the coil.

Electromagnets and bar magnets have similar characteristics with north and south poles, but differ in that electromagnets need a power supply while bar magnets are permanent.

Electromagnets and bar magnets share similarities such as having north and south poles that attract and repel each other. They both produce a magnetic field around them.

However, electromagnets require an external power supply to generate a magnetic field, while bar magnets are permanent magnets that do not need an external power source.

Answer:

In a polar covalent bond, the electrons are unequally shared by the atoms and spend more time close to one atom than the other.

Explanation:

Answer: polar covalent bonding

Explanation:

A polar covalent bond is defined as the bond which is formed when there is a difference of electronegativities between the atoms.

Ionic bond is formed when there is complete transfer of electron from one atom to another atom.

Non-polar covalent bond is defined as the bond which is formed when there is no difference of electronegativities between the atoms.

Water molecules are bonded by strong hydrogen bonding between the hydrogen atom and the electronegative oxygen atom by sharing of electrons and thus form polar covalent bonds.

Answer:

The brick would heat up the fastest.

Explanation:

Bricks are thick but they absorb sunlight at an alarming rate.

A. brick

In thermodynamics, the specific heat capacity of a substance is the heat capacity of a sample of the substance divided by the mass of the sample, also sometimes referred to as massic heat capability.

specific heat is the amount of energy, measured in joules, needed to increase the temperature of 1 gram of the substance by one Celsius degree. often carried out to metallic elements, specific heat can be used as a basis for comparing how different materials absorb and transfer energy.

Learn more about specific heat capacity here

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p=mv

a).p=(0.003kg)(9m/s)+(0.05kg)(0m/s)=0.027kg*m/s

Answer:

a) 0.027 kgm/s

b) 0.027 kgm/s

c) 0.509 m/s

Explanation:

Mass of gum = m1 = 0.003 kg  

Mass of box = m2 = 0.05 kg  

Velocity of gum before collision = V1 = 9 m/s  

Velocity of box before collision = V2 = 0 m/s  

a) Momentum of system before collision = m1V1 – m2V2

                                    = (0.003)(9) – (0.05)(0) = 0.027 kgm/s  

b)According to law of conservation of momentum,

Momentum of system after collision = Momentum of system before collision

                                  Momentum of system after collision = 0.027 kg/s

c) as the gum and box behaving as a single object so their velocity (V’) will be same.

Momentum of system after collision = (m1 + m2)V’ = 0.027 kg/s

                                                            V’ = 0.027/(m1 + m2)

                                                            V’ = 0.027/(0.003 + 0.05)

                                                             V’ = 0.509 m/s

- "Gravity is a universal attraction between any two objects with mass. Every object in the universe is affected by the force of gravity. The two factors that affect the magnitude of gravity are the mass of the attracted objects and the distance between them. The greater the masses the greater the gravitational force between two objects."

Answer: True

Explanation:

Answer:

37 ft

Explanation:

First find the air time:

y = y₀ + v₀ᵧ t + ½ gt²

0 = 0 + (36 sin 56°) t + ½ (-32.2) t²

0 = 29.8 t - 16.1 t²

0 = t (28.8 - 16.1 t)

t = 1.85 s

Now find the range:

x = x₀ + v₀ t + ½ at²

x = 0 + (36 cos 56°) (1.85) + ½ (0) (1.85)²

x = 37.3 ft

Rounded to two sig-figs, the range is 37 feet.

The range of a projectile launched at an angle of 56° above the horizontal with an initial velocity of 36 ft/s, neglecting air resistance and considering that the launch and landing sites are at the same elevation, is approximately 129.17 ft.

In Physics, the range of a projectile launched at an angle can be calculated with the following equation: Range = (v² sin 2θ )/ g where v is the initial velocity, θ is the launch angle, and g is the acceleration due to gravity.

In this case, v = 36 ft/s, θ = 56°, and g = 32.2 ft/s². Converting the angle from degrees to radians gives us θ = 56° × π/180 = 0.977 radians.

Plugging in the values and using the sine of double the angle, we have: Range = (36 ft/s)^2 sin(2 * 0.977 rad) / 32.2 ft/s² = 129.17 ft.

So, the range of the projectile, assuming negligible air resistance and the launch and landing sites are at the same elevation, is approximately 129.17 ft.

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Answer:

The direction of where the wind comes from normally in Enfield, Connecticut is from the southeast.

Hope this helps!! :)

In Enfield, we normally expect weather to approach from the west. This is due to the prevailing westerly winds that affect the weather patterns in the United Kingdom. Consequently, weather systems often move in from the Atlantic Ocean, which lies to the west of Enfield and the rest of the UK.

The predominant weather direction in Enfield is influenced by the larger atmospheric circulation patterns, specifically the westerly winds found in the UK's latitudinal zone. These winds are part of the global circulation system and are driven by the Earth's rotation and the temperature contrast between the equator and the poles. As a result, low-pressure systems, which generally bring cloudy and rainy conditions, commonly move from west to east due to these westerly winds. Understanding this pattern is crucial when describing the weather of Enfield at a specific time. Additionally, detailed weather forecasts for Enfield would take into account these prevailing winds and other local factors that might slightly alter this general west to east movement.

Answer:

radiation

Explanation:

Answer:

radio waves, microwaves, infrared waves, visible light, ultraviolet waves, X-rays, gamma rays

Explanation:

Answer:

Neither. But I guess, if you look at it this way, they make up rocks... so I guess D is probably the most likely answer of those options. Hope this helps.

I think that the answer is C but give me a minute to make sure I’m correct

the discovery by Nikola tesla that out-of-phase alternating currents caused rotation is considered one of the 10 greatest scientific discoveries.

A movement of charged particles, such as electrons or ions, through an electrical conductor or a vacuum is known as an electric current. The net rate of electric charge flow through a surface is how it is described Charge carriers, which can be any of a number of particle kinds depending on the conductor, are the moving particles. Electrons flowing over a wire are frequently used as charge carriers in electric circuits. They can be electrons or holes in semiconductors. Ions are the charge carriers in an electrolyte, whereas ions and electrons are the charge carriers in plasma, an ionized gas.

The passage of electric charge across a surface at a rate of one ampere is the SI unit for electric current.

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The reason behind the second hill in the roller coaster not taller than the first hill is the frictional force acting on the roller coaster.

Explanation:

The height of the first hill in the roller coaster is taller with the decrease in the subsequent hills as the frictional forces reduces the kinetic energy.  

Coming down the first tallest hill, the speed and kinetic energy both increases as the motion is in line with gravity, but due to conservation of energy, the potential energy decreases. And as the potential energy decreases, the height of hill has to be decreased in order to complete the motion.

Answer:

no, because the waves do not have the same amplitude

Explanation:

Answer:

384 N

Explanation:

Newton's second law:

∑F = ma

F = (32 kg) (12 m/s²)

F = 384 N

Answer:

F=384 N

Explanation:

F=ma

F = 32 kg × 12 m/s2

F = 384 N

#PennFoster

Answer:

0.044 amps

Explanation:

Givens

R = 2500 ohms

E = 110 volts

I = ?

Equation

I = E/R

Solution

I = 110/2500

I = 0.044 amps

After 5 seconds, the rock would be traveling at 49 m/s provided there is no air resistance.

To determine the speed of the rock after 5 seconds of free fall without air resistance, we can use the equation of motion under constant acceleration due to gravity. The relevant formula, which is derived from the laws of motion, is:

v = u + at

Where:

v is the final velocity (what we want to find)

u is the initial velocity

a is the acceleration due to gravity (approximately 9.8 m/s² on Earth)

t is the time for which the object has been falling

Since the rock is dropped (meaning no initial velocity), u = 0 m/s. Thus, the equation simplifies to:

v = at

Substituting known values, we get:

v = 9.8 m/s²×5 s

v = 49 m/s

The speed of the rock after falling for 5 seconds from a cliff, in the absence of air resistance, can be calculated using the formula v = gt, where g is the acceleration due to gravity. After 5 seconds, the rock's speed will be 49 m/s.

The question asks for the speed of the rock after 5 seconds if it is dropped from a cliff with no air resistance. To solve this, we can utilize the formula for the velocity of a falling object due to gravity, which is v = gt, where 'v' is velocity, 'g' is the acceleration due to gravity (approximately 9.8 [tex]m/s^2[/tex] on Earth), and 't' is the time in seconds.

In this case, the initial speed is 0 m/s, so after 5 seconds the speed of the rock would be:

v = 9.8 [tex]m/s^2[/tex] × 5 s = 49 m/s

Therefore, the rock's speed after 5 seconds will be 49 m/s, assuming that there is no air resistance.

Answer:

the answer is the last one

The electronic signs along the highway are run by solar power ​- this statement best describes to use for non-renewable resource.

A nonrenewable resource exists as a substance that is being utilized more quickly than it can substitute itself. Most fossil fuels, minerals, and metal ores exist as nonrenewable resources. Renewable resources such as solar and wind power and water exist unlimited in supply. Non-renewable energy creates up 95 percent of the world’s electricity needs. Most sources of non-renewable energy exist as fossil fuels such as petroleum, coal, gas, and oil. on-renewable energy exists energy sources that will ultimately run out when put to work.

The correct answer is option D.

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Answer:

8) inertia

9) mass and velocity

10) electric

11) decreases because gravity decreases

Hello There

Newtons first law of motion is sometimes called the law of "INERTIA"

Momentum depends on "MASS AND VELOCITY"

What force is responsible for the repulsion between two positively charged particles? "ELECTRIC"

An astronaut travels far away from Earth, her weight "DECREASES BECAUSE GRAVITY DECREASES"

Can you give us the statements?