a piece of aluminum foil measures 6.74 cm by 6.86 cm and has a mass 0.326 g. the density of aluminum is 2.70 g/cm3. what is the thickness of the foil in cm? write the answer in standard decimal notation with correct significant figures.

Answer:

Electromagnetic waves are visible; mechanical waves are invisible. Electromagnetic waves always reflect; mechanical waves always refract.

Explanation:

Answer:

well you already answered yourself i don't see why you would waist points to do that but yes you are correct .

Explanation:

stay safe and where a mask 2021

The photoelectric effect is observed when light interacts with matter, specifically when photons (particles of light) transfer their energy to electrons in an atom or a material. The correct answer is A. When an electric current results from light shining on a surface.

In the early 20th century, Albert Einstein provided a groundbreaking explanation of the photoelectric effect, which earned him the Nobel Prize in Physics in 1921. His work established the dual nature of light, both as a wave and as a particle (photon). Here's a detailed explanation of the photoelectric effect:

When light shines on a surface, it is composed of photons that carry energy. These photons interact with electrons in the material. The photoelectric effect occurs when photons transfer their energy to electrons, causing them to be emitted from the material.

The process can be described in several steps:

1. Absorption: When a photon with sufficient energy interacts with an electron in an atom or material, it can be absorbed. The energy of the photon is transferred to the electron, promoting it to a higher energy level or even releasing it from the atom.

2. Ejection: If the energy of the absorbed photon is greater than or equal to the binding energy of the electron (also known as the work function), the electron can be ejected from the material. The work function represents the minimum energy required to remove an electron from the material's surface.

3. Electron emission: The ejected electron can now contribute to the formation of an electric current. If there is a conducting material connected to the surface, the released electron can move through the material, resulting in the flow of electric charge.

The photoelectric effect is not observed when light acts solely as a wave (option B). While light does exhibit wave-like properties, such as interference and diffraction, these phenomena do not directly involve the transfer of energy from photons to electrons.

Option C, "When an electric current causes light to be produced," does not accurately describe the photoelectric effect. The photoelectric effect involves the emission of electrons due to the interaction of light with matter, but it does not directly produce light as a result of an electric current.

Option D, "Any time an electric current is produced," is a broad statement that encompasses various phenomena beyond the photoelectric effect. Electric currents can be produced in various ways, such as through the flow of charged particles or the movement of electrons in a conductor. The photoelectric effect is a specific phenomenon that occurs when light interacts with matter and results in the emission of electrons.

To summarize, the photoelectric effect is observed when light shines on a surface, and the energy of photons is transferred to electrons, leading to their emission from the material. This emission of electrons can result in the formation of an electric current.

For more questions on photons, click on:

https://brainly.com/question/15946945

#SPJ8

I think it is the question:

When is the photoelectric effect observed?

A. When an electric current results from light shining on a surface

B. When light acts as a wave

C. When an electric current causes light to be produced

D. Any time an electric current is produced .

Answer:

Assuming they're unit vectors (length of 1)

You simply add them together.

The vector pointing right can be described with X and Y

(1, 0).

The vector pointing down

(0, -1).

The numbers are taken from the axis in X and Y directions.

If you add them together you get a final vector.

(1, - 1)

This gives you -45° pointing South East.

Or 360°-45°=315°

Answer:

\(Speed = \frac{8v}{5}\)

Explanation:

Given

\(Speeds: v\ and\ 2v\)

Required

Determine the average speed

First, we need to determine the time spent on the journey

\(Time = Distance/Speed\)

For the first \(\frac{1}{4}th\)

\(T_1 = \frac{1}{4}/v\)

\(T_1 =\frac{1}{4v}\)

For the next \(\frac{3}{4}th\)

\(T_2 = \frac{3}{4}/2v\)

\(T_2 = \frac{3}{8v}\)

\(Total\ Time = T_1 +T_2\)

\(T = \frac{1}{4v} + \frac{3}{8v}\)

\(T = \frac{2+3}{8v}\)

\(T = \frac{5}{8v}\)

Average Speed is then calculated as thus:

\(Speed = Distance/Time\)

\(Speed = (\frac{1}{4} + \frac{3}{4})/\frac{5}{8v}\)

\(Speed = (\frac{1+3}{4})/\frac{5}{8v}\)

\(Speed = (\frac{4}{4})/\frac{5}{8v}\)

\(Speed = 1/\frac{5}{8v}\)

\(Speed = 1 * \frac{8v}{5}\)

\(Speed = \frac{8v}{5}\)

Hence;

Option 1 answers the question

Answer: 1. \(\frac{8v}{5}\)

Explanation: Speed is a variable in Physics defined by the rate at which an object go through a distance. It can be calculated as:

\(speed=\frac{distance}{time}\)

A fourth of distance with speed v takes:

\(speed=\frac{distance}{time}\)

\(time=\frac{distance}{speed}\)

\(time=\frac{1}{4v}\)

The rest of the distance with speed 2v takes:

\(time=\frac{3}{4*2v}\)

\(time=\frac{3}{8v}\)

Average speed is given by:

\(average=\frac{distance_{traveled}}{time_{travel}}\)

Total time to cover the distance:

\(time=\frac{1}{4v}+\frac{3}{8v}\)

\(time=\frac{2+3}{8v}\)

\(time=\frac{5}{8v}\)

Total distance traveled:

\(d=\frac{1}{4} +\frac{3}{4}\)

d = 1

average = 1 ÷ \(\frac{5}{8v}\)

\(average=\frac{8v}{5}\)

The average speed of particle is 8/5v.

Answer:

When you have two materials with the same index of refraction, it means that if they are touched by a ray of light it won't have a chance, and its form would prevail.

Explanation:

The reason behind this is that in the first place. When light passes through an object of certain refraction it is modified from its natural state, allowing it to change in color to the human eye or many other effects in other perceptive elements. However, when the same light passes through two objects with the same refraction due to their physical characteristics, it doesn't change because once it comes out of the first one it will suffer the same effect from the last one. For it to change the refraction would have to be higher or lower. Then it would be modified. The reason is because the dimensions are not modified. Because at some point the ray of light has to come out of the first one to enter the second one.

Answer:

Distance is a scalar quantity that refers to "how much ground an object has covered" during its motion. Displacement is a vector quantity that refers to "how far out of place an object is"; it is the object's overall change in position.

Explanation:

Answer:

Distance is like school is 5 minutes from my house or the store is 2 miles for somewhere. Displacement is when you miss place or loss something, such as you lay your phone down and cant find it.  

Explanation:

hope this helps, have a great day!

The power is generated by the machine that lifts the 50 kg box a

distance of 15 m in 8 seconds is 918.75 W (2nd option)

We'll begin by obtaining the work done by the machine in lifting the box. Details below:

Wd = mgh

Wd = 50 × 9.8 × 15

Wd = 7350 J

Finally, we shall determine the power generated. Details below:

P = Wd / t

P = 7350 / 8

P = 918.75 W

Thus, the power generated is 918.75 W (2nd option)

Learn more about power:

https://brainly.com/question/30817666

#SPJ1

First we make a representation of the situation by building a free body diagram as attached in the figure.

We write the sum of forces on the axis of motion as:

\(P_x -fr = ma\\a = \dfrac{P_x-fr}{m}\\a = \dfrac{mg\sin \theta -fr}{m}\\\\a = \dfrac{(12\;kg)(9.8\;m/s^2)\sin 40^\circ -60N}{12\;kg}\\\\a\approx1.3 \;m/s^2\)

b) We know from cinematic that:

d = at²/2

Solving for t:

\(t = \sqrt{\dfrac{2d}{a}} =\sqrt{\dfrac{2(5\;m)}{1.3\;m/s^2}} = 2.8\;s\)

c) We write the sum of forces on the y axis as:

N - Py = 0

N = Py

N = mgcosθ

fr = μN

Solving for μ:

μ = fr/N

\(\mu = \dfrac{fr}{mg\cos\theta} = \dfrac{60\;N}{(12\;kg)(9.8\;m/s^2)\cos40^\circ} =0.67\)

1. The acceleration of the box is 1.3 m/s^2.

2. The time taken for reaching the bottom of the incline is 2.8 seconds.

3. The coefficient of friction is 0.67.

1.

We know that

Px - fr = ma

a = (px - fr)/m

a = (mg sin - fr)/m

= (12) (9.8) sin 0 - 60 N / 12 kg

= 1.3 m/s^2

2. The time taken should be

= √2d/a

= √295) / 1.3

= 2.8 seconds

c. The coefficient of friction should be

N - Py = 0

N = Py

μ = fr/mgcos

= 60N /  (12kg) (9.8) (cos 40)

= 0.67

Learn more about acceleration here: https://brainly.com/question/24759048

Answer:

acceleration...............

Answer:

speed

Explanation:

wanna see some real speed betch

Answer:

the human body isn't very efficient at converting food into useful work. The human body is less than 5% efficient most of the time. The rest of the energy is converted to heat, which may or may not be useful, depending on how cool or warm a person wants to be.

Explanation:

Answer:

both

Explanation:

The frequency you hear if the cop was driving away from you at a speed of 25 m/s is  652 Hz. The correct option is C.

It is the number of oscillations per second of the sinusoidal wave.

A cop car’s siren has a frequency of 700. H z. If you are standing on the sidewalk as the cop car approaches you at a speed of 15.0 m/ s.

The cop was driving away from you at a speed of 25 m/s. The speed of sound is 343 m/ s.

The frequency you hear will be calculated using the following formula

f' = f(Vs - Vo)/(Vs +Vc)

Substitute the values into the above equation, we get

f' = 700 x (343 - 0) / (343 + 25)

f' = 652.45 Hz

or f' = 652 Hz

Thus, the frequency you hear when the cop is driving away is  652 Hz.

Learn more about frequency.

https://brainly.com/question/13758580

#SPJ1

Answer: Traveling wave

Explanation:

Magnets are preserved in the following ways except by, option A, hammering them in east-west direction.

A magnet can lose its magnetic characteristics when hammered in either direction, whether or not it is in the east-west direction. This is because hammering can cause the magnetic domains in the magnet to become disordered and random, which weakens or destroys the magnet's magnetic field.

The other options mentioned in the question, such as not altering the current through a coil, not knocking the magnets with objects, placing a non-magnetic object in between them, and placing them in opposite directions, are all ways to preserve the magnetic properties of magnets.

To know more about magnets, visit,

https://brainly.com/question/14997726

#SPJ1

The magnetic field of Uranus and Neptune is weaker than that of Jupiter and Saturn but stronger than Earth's. Thus, the correct option is the third option: moderate strength.

Uranus and Neptune, two outer planets in our Solar System, have magnetic fields that are much weaker than those of Jupiter and Saturn, but still stronger than Earth's. The magnetic field of Uranus is tilted at an angle of 59 degrees to its axis of rotation, while Neptune's magnetic field is tilted at an angle of 47 degrees. Uranus has a very irregular magnetic field that is shifted off-center and is believed to be lopsided, with its magnetic north pole nearer to the equator than to the geographic north pole. Neptune's magnetic field is also somewhat skewed, but not to the same extent as Uranus'.

Learn more about magnetic field visit:

brainly.com/question/14848188

#SPJ11

Answer: A E F H

Explanation: Hey I'm Lola I'm happy to help you I'm 16 years old! :D

Answer:it’s actually BCD

Explanation:

you’re welcome

A concentration cell is a type of electrochemical cell in which the same electrode material is used as both the anode and cathode, but the concentrations of the reactants or products are different in each half-cell.

The correct  answer is: c. zero.

In a concentration cell, the standard cell potential is always zero because there is no net driving force for electron transfer since both electrodes are identical in composition and potential. However, there will be a non-zero voltage if the concentrations of the solutions are different, which can cause a flow of electrons from the more concentrated half-cell to the less concentrated half-cell until equilibrium is reached.

A concentration cell is an electrochemical cell where the two electrodes are made of the same material and are immersed in solutions with different concentrations. The standard cell potential, denoted as E°, is the difference in potential between the two half-cells under standard conditions (1 M concentration, 1 atm pressure, and 25°C temperature). In a concentration cell, both half-cells have the same standard reduction potential, so their difference (E°) will be zero.

To know more about electrochemical visit:

https://brainly.com/question/12034258

#SPJ11

(a) The acceleration of the system is 28.55 m/s².

(b) The tension in the rope is 285.5 N.

The acceleration of the box is determined by applying Newton's second law of motion as follows;

F(net) = ma

where

weight of 30 kg mass - force of friction due to 10 kg  = tension in the rope

Fg - μmgcosθ  = ma

(30 kg x 9.8 m/s²) - (0.1 x 10 kg x 9.8 x cos30) = 10a

294 - 8.49 = 10a

285.51 = 10a

a = 285.51/10

a = 28.55 m/s²

The tension in the rope is calculated as follows;

T = ma

T = 28.55 m/s² x 10 kg

T = 285.5 N

Thus, the acceleration of the system depends on the masses and force of friction on the blocks

Learn more about tension in rope here: https://brainly.com/question/187404

#SPJ1

To calculate the net torque required, you can use the formula:

Net torque = I * α

Where I am the moment of inertia of the solid ball and α is the angular acceleration.

For a solid ball, the moment of inertia (I) is given by:

I = (2/5) * m * r^2
where m is the mass and r is the radius of the ball.

Now, plug in the given values:

I = (2/5) * 20 kg * (0.20 m)^2
I = 0.32 kg m^2
Next, multiply the moment of inertia (I) by the angular acceleration (α):

Net torque = 0.32 kg m^2 * 20 rad/s^2
Net torque = 6.4 N m

What is torque?

Torque is a measure of a force's ability to rotate an object around an axis or pivot point. When the force is perpendicular to the object's axis of rotation, it is most effective. Torque is a measure of an object's "rotational motion. "Torque is expressed in newton-meters (N-m) or pound-feet (lb-ft) in the metric system (ft-lb). In simple terms, torque is the product of force and the distance from the point of rotation to the point where the force is being applied. Formula to calculate net torque is equal to the product of the force and the lever arm, which is the distance between the pivot point and the point at which the force is applied. The net torque can be calculated using the following formula: Net Torque = Lever arm x Applied force Where Net torque is the resultant torque acting on an object. The lever arm is the distance from the pivot point to the force being applied. The applied force is the force applied. It can be any type of force, such as gravitational force, frictional force, or electrical force.
So, the net torque required is 6.4 N m.

Learn more about net torque here:

https://brainly.com/question/29048159

#SPJ11

The correct answer is B. According to Newton's law of universal gravitation, the gravitational force between two objects is directly proportional to the product of their masses and inversely proportional to the square of the distance between their centers.

In simpler terms, as objects get closer together, the gravitational force between them increases.

When the distance between two objects decreases, the denominator of the equation (distance squared) becomes smaller, resulting in a larger force. Conversely, when the distance increases, the denominator becomes larger, resulting in a smaller force.

It is important to note that the mass of an object does not directly affect the strength of the gravitational force between two objects. However, a higher mass will lead to a greater gravitational force when compared to a lower mass, but only because the force is being exerted on a more massive object. The mass of an individual object doesn't directly affect the gravitational force it experiences from another object. option B

for more questions on gravitational force

https://brainly.com/question/27943482

#SPJ8

Answer:

6.8×10^6 m

Explanation:

f = velocity of light/ wavelength

440= 3×10^8 / wavelength

so

wavelength = 3×10^7/ 44

= 6.8×10^6 m

The distance of separation between the two masses is 0.927 m.

This is the force that exists between two masses in the universe.

To calculate the distance of separation of the masses, we use the formula below.

Where:

Make r the subject of the equation.

From the question,

Given:

Substitute these values into equation 2

Hence, The distance of separation between the two masses is 0.927 m

Learn more about Gravitational force here: https://brainly.com/question/11359658

Answer:

D :)

Explanation:

When an impact causes the car to suddenly change its motion, (D) the people in the car will continue to move in the same direction and at the same speed as before the impact.

Newton's first law of motion states that Unless influenced by an imbalanced force, a body at rest stays at rest, and a body in motion keeps moving in a straight path at a constant pace. This law is commonly known as law of inertia and the resistance of a body to maintain its state of rest is called inertia of rest, same as, the resistance of a body to maintain its state of motion is called inertia of motion.

When a car is moving with certain speed, the car along with the people inside the car is in inertia of motion. In an event of accident, the car comes in rest in no time but the man in the car is still in inertia of motion. So, his body moves forward in the car which may cause injuries. To prevent such injuries, the people inside a car are advised to use safety belts.

So, correct answer  is option (D).

Learn more about Newton's first law of motion here:

https://brainly.com/question/974124

#SPJ2

Answer:

Ionic compounds conduct electricity when dissolved in water

Explanation:

The comparison of two quantities by division of two similar quantities is called ratio and proportion and the given statement is true.

A ratio is a way of comparing amounts. A ratio shows the number of times an amount is contained in another, or how much bigger one amount is than another.

The two numbers are both parts of the whole, If I need to mix some cement, then I could add two parts cement to four parts sand. Hence the ratio 2:4 (6 parts in total). The written bis important; 4:2 would give a different mix.

Ratios are written to their simplest form. In the figure to the right we have 15 red dots and five green dots. The ratio is 15:5; however, this can be reduced to the simplest form as we do with fractions.

The ratio as we can see in the graphic is also 3:1, if you look at the relationship of the numbers 15:5 as is 3:1, we can see that 3 is multiplied by 5 to get 15 and so is the one to get five.

To know more about propotion here

https://brainly.com/question/870035

#SPJ4

Given that the progressive wave equation is represented by y=Asin2π(0.15t-0.1x). Let's find the period, amplitude, frequency, wavelength, and velocity.

The wave equation is represented by y=Asin2π(0.15t-0.1x). The standard wave equation can be written asy = Asin(kx-ωt + Φ)Where,k = wave numberω = angular frequencyΦ = phase angle for the given equation, k = 0.1 and ω = 0.15.Amplitude:

Amplitude = A = maximum displacement from the mean position.A = 1Frequency: Frequency is the number of complete oscillations made by a point on the wave in one second. It is denoted by f.f = ω/2πFrequency, f = 0.15/2π = 0.0238 HzPeriod: Period is the time taken by one complete oscillation.

To know more about wavelength visit:

https://brainly.com/question/31143857

#SPJ11

When using the binding energy versus nucleon number, if the amount of binding energy per nucleon is high, the answer is A. yes.

A nucleon is a proton or a neutron, two types of particles present in the nucleus of an atom. When studying nuclei and nuclear reactions, the nucleon is used to represent these particles. Binding energy is the energy that is required to break the nucleus into individual nucleons. A large binding energy per nucleon is a sign of a strong nuclear force, and therefore, a strong nucleus. When the binding energy per nucleon is high, it indicates that the nucleons are tightly bound in the nucleus and that there is a strong force holding them together. As a result, the nucleus is more stable and less likely to undergo nuclear reactions. Answer option A.

More on nucleon number: https://brainly.com/question/14622763

#SPJ11

Answer:

(D) None

Explanation:

The force of gravity is the force pulling every element of matter together. The more the matter the higher the force of gravity.

Examples of this force at work are;

The force that facilitates a pen on your hand to write on a paper is friction force between the pen and the paper. Gravitational force acts downwards thus force applied on an object beside you is not the force of gravity.

Answer:

Unsaturated

Explanation:

the solubility of sodium nitrate is at 60 C is 124g/ml therefore, putting 100 grams will not saturate fully.