John and Henry push a piano with 800N, and the piano refuses to move. According to the definition of work in physics, there is NO work done on the piano.

Answers

Answer 1

Answer:

Explanation:

This is true because the definition of work is the parallel force required to move an object times the distance it moves. If it doesn't move, no work has been done. That is not to say that no energy has been expended, because it most certainly has! But that is not the same thing.


Related Questions

If the oil film becomes dark when the path length difference is less than one fourth the wavelength, what is the thickest the oil film can be and appear dark at all visible wavelengths

Answers

His question is incomplete, the complete question is;

A film oil on water will appear dark when it is very thin, because the path length difference becomes small compared with the wavelength of light and there is a phase shift at the top surface.

If the oil film becomes dark when the path length difference is less than one fourth the wavelength, what is the thickest the oil film can be and appear dark at all visible wavelengths. Oil has an index of fraction of 1.40.

In this question, assume the wavelength visible light is in the range of 400 nm to 700 nm.

Answer:

the minimum thickness of the oil for destructive interference to occur is approximately 35.714 nm

Explanation:

Given the data in the question;

Path difference for destructive interference between the two reflected waves ( top and bottom );

δ = 2nt ---------- let this be equation 1

Also, for one path difference of reflected waves, one fourth of the wavelength of reflected waves;

δ = λ/4 ---------- let this be equation 2

from equation 1 and 2;

δ = δ

2nt =  λ/4

we find t;

8nt =  λ

t = λ / 8n

given that; λ[tex]_{minimum[/tex] = 400 nm and n = 1.40

we substitute

t = 400nm / 8(1.40)

t = 400nm / 11.2

t = 35.7142857 ≈ 35.714 nm

Therefore, the minimum thickness of the oil for destructive interference to occur is approximately 35.714 nm

True or False? The most reactive metals are found in Period 1 of the Periodic Table.

Answers

Hydrogen is a very reactive gas, and the alkali metals are even more reactive. In fact, they are the most reactive metals and, along with the elements in group 17, are the most reactive of all elements.

Answer:

Explanation:

true

newton's second law states that when a net force acts on an object, it accelerates it.Explain how it would be possible for two or more forces to act on object without accelerating it

Answers

Answer:

See Explanation

Explanation:

According to Newton's second law of motion, the acceleration of a body is proportional to the net external force that acts on the body.

A body accelerated when it is acted upon by an unbalanced net external force.

When the external forces acting on a body are balanced, the effect of each force is cancelled by the other hence the body is not accelerated according to Newton's second law.

A ball rolled 12.0 m [E] in 10.0 s, hit an obstacle, and rolled straight back. After the collision, the ball rolled 8.00 m [W] in 6.00 s. What was the average velocity of the ball?

Answers

Answer:

the average velocity of the ball is 5 m/s.

Explanation:

Given;

initial position of the ball, x₁ = 12 m East

final position of the ball, x₂ = 8 m West

initial time of motion, t₁ = 10.0 s

final time of motion, t₂ = 6.0 s

The average velocity is calculated as follows;

[tex]v = \frac{\Delta x}{\Delta t} = \frac{x_1 \ - \ x_2}{t_1 \ - \ t_2}[/tex]

let the Eastward direction be positive

Let the westward direction be negative

[tex]\frac{x_1 \ - \ x_2}{t_1 \ - \ t_2} = \frac{12 \ - \ (-8)}{10 -6}= \frac{20}{4} = 5 \ m/s[/tex]

Therefore, the average velocity of the ball is 5 m/s.

A force is applied to a 12 kg box. The force is applied parallel to the motion of the box. Determine the force acting on the box if it moves 22 meters and increases the box’s speed from 10 m/s to 25 m/s.

Answers

Answer:

Force = 143.16 Newton

Explanation:

Given the following data;

Distance, S = 22 m

Initial velocity, U = 10 m/s

Final velocity, V = 25 m/s

Mass = 12 kg

To find the force acting on the box;

First of all, we would determine the acceleration of the box using the third equation of motion;

V² = U² + 2aS

25² = 10² + 2*a*22

625 = 100 + 44a

625 - 100 = 44a

525 = 44a

Acceleration, a = 525/44

Acceleration, a = 11.93 m/s²

Next, we find the force;

Force = mass * acceleration

Force = 12 * 11.93

Force = 143.16 Newton

Which property determines and Adams ability to attract electrons shared in a chemical bond?

Answers

Answer:

Electronegativity

Explanation:

Answer:

The property that determines an atom;s ability to attract electrons shared in a chemical bond is electronegativity.

Explanation:

Hope you have a great day :)

Which explanation best describes a wave?
A.
a disturbance that travels through a medium with a transfer of energy and matter
B.
a disturbance that travels through a medium without a transfer of energy and matter
C.
a disturbance that travels through a medium with a transfer of energy and without a transfer of matter
D.
a disturbance that travels through a medium with a transfer of matter and without a transfer of energy
E.
a disturbance that travels only in the absence of a material medium

Answers

Answer:

C. a disturbance that travels through a medium with a transfer of energy and without a transfer of matter

Explanation:

A wave is any disturbance that transfers energy from one location to the other via a substance called medium. It is important to note that a wave only conveys energy and not matter. For example, sound wave is a type of wave that carries sound energy from one place to another via mediums such as water, air etc.

Hence, according to this question, a wave can be described as a disturbance that travels through a medium with a transfer of energy and WITHOUT A TRANSFER OF MATTER.

Two boxes are connected by a string. The first box has a mass of 4.2 kg and the
second 2.8 kg. A string attached to the first box pulls horizontally with a force of
7.5 N. Calculate the tension in the second string if the force of friction on the first
box is 2.0 N and the force of friction on the second is 1.6 N.

Answers

Answer:

........

Explanation:

A measurement of a change
in distance over time

Answers

Explanation:

Speed is the rate of change of distance with time.

¿Cuál es la intensidad del campo eléctrico a una distancia de 2 m de una carga de -12μC? *

Answers

Answer:

Una secadora de cabello tiene una resistencia de 10Ω al circular una corriente de 6 Amperes, si está conectado a una diferencia de potencial de 120 V, durante 18 minutos ¿Qué cantidUna secadora de cabello tiene una resistencia de 10Ω al circular una corriente de 6 Amperes, si está conectado a una diferencia de potencial de 120 V, durante 18 minutos ¿Qué cantidad de calor produce?, expresado en caloríasad de calor produce?, expresado en calorías

In what ways do people use natural resources? What problems does use of those resources cause?

Answers

Answer:

The Challenges of Using Natural Resources

Extracting, processing and using natural resources can cause environmental problems such as: air, land and water pollution; disruption or destruction of ecosystems; and a decrease in biodiversity.

Which of the following is a disadvantage of a parallel circuit? A. Parallel circuits are a complex circuit and use more wire. B. If one bulb goes out the others go out too. C. Each of the bulbs burn at a different level of brightness.​

Answers

B. If one bulb goes out the others go out too.( if the circuit is broken anywhere all the bulbs stop working)

What object currently has the most gravitational potential energy?

A, B, C, or D​

Answers

Answer:

A

Explanation:

this because

gravitational potential energy = mass x height x gravitational field strength

so let's assume mass is 2 kg and gravitational field strength is 10 N /kg

so when height is very low, take it as 3 m

gravitational potential energy= 2 x 3 x 10 = 60 j

but when height is 6m

gravitational potential energy = 2 x 6 x 10 = 120 j

so when the height is the greatest, the gravitational potential energy is the highest

so A is the heighest so it has the highest gravitational potential energy.

hope this helps

please mark it brainliest :D

A woman on a 10-speed bicycle travels at 9m/s relative to the ground as she passes a little boy on a tricycle going in the opposite direction. If the boy is travelling at 1m/s relative to the ground , how fast does the boy appear to be moving relative to the woman

Answers

Answer:

23

Explanation:

why are the layers of the earth in the order that they are in?

Answers

Answer:

Each layer has its own properties, composition, and characteristics that affects many of the key processes of our planet. They are, in order from the exterior to the interior – the crust, the mantle, the outer core, and the inner core.

Explanation:

it’s due to the relative melting points of the different layers and increase of the temperature as depth increases

Two boulders have masses of 7.5 x 106 kg and 9.2 x 105 kg. After rolling apart, their centers are separated by a distance of 124 m. Find the gravitational attraction FG between them.

Answers

Answer:

0.0299 N

Explanation:

Applying,

F = Gmm'/r²................... Equation 1

Where F = gravitational force between the boulders, m = mass of the first boulder, m' = mass of the second boulder, r = distance between the boulders, G = Universal constant.

From the question,

Given: m = 7.5×10⁶ kg, m' = 9.2×10⁵ kg, r = 124 m

Constant: G = 6.67×10⁻¹¹ Nm²/kg²

Substitute these values into equation 1

F = (6.67×10⁻¹¹× 7.5×10⁶ × 9.2×10⁵ )/124²

F = (460.23)/15376

F = 0.0299 N

Answer:

0.3 N

Explanation:

Plug in all your variables:

6.67 ⋅ 10^-11 (7.5 ⋅ 10^6) (9.2 ⋅ 10^5)

                    --------------------------------

                                 (124)^2

Once you plugin, You start to multiple solving to solve your problem:

460.23

----------      = 0.02993171 N

15376

Now Simplify:

Answer = 0.03 N

Please Help!!!!

Your Best friend gets on a ship and travels away fast. They return 10.0 years later and I’ve only aged 4.00 years. How fast was your friend traveling? Give your answer as ex. 0.5c

Answers

Answer:

v = 0.92 c

Explanation:

Here, we will use the time dilation formula from Einstein's theory of relativity to find the speed of traveling of the friend:

[tex]t =\frac{t_o}{\sqrt{1-\frac{v^2}{c^2}}} \\\\\\\sqrt{1-\frac{v^2}{c^2}}=\frac{t_o}{t}\\\\[/tex]

where,

v = speed of traveling = ?

c = speed of light

t = time of return = 10 years

t₀ = time passed on earth = 4 years

Therefore,

[tex]\sqrt{1-\frac{v^2}{c^2}} = \frac{4\ years}{10\ years}\\\\ 1-\frac{v^2}{c^2}=(\frac{2}{5})^2\\\\\frac{v^2}{c^2} = 1-\frac{4}{25}\\\\\frac{v^2}{c^2} = \frac{21}{25}\\\\v^2 = 0.84c^2\\\\[/tex]

v = 0.92 c

5- A 2.0 kg block of aluminum (specific heat = 897 J/kg·K) is at an initial temperature of 300 K. What will its final temperature be if (3.35 × 105 J )of thermal energy is transferred to the block?

Answers

Answer:

T = 486.6 K

Explanation:

The final temperature of the block can be found using the following formula:

[tex]Q = mC\Delta T\\[/tex]

where,

Q = Thermal Energy Transferred = 3.35 x 10⁵ J

m = mass of aluminum block = 2 kg

C = Specific Heat = 897 J/kg.K

ΔT = Change in Temperature = T - 300 K

T = Final Temperature of the Block = ?

Therefore,

[tex]3.35\ x\ 10^5\ J = (2\ kg)(897\ J/kg.K)(T-300\ K)\\\\5.38\ x\ 10^5\ J + 3.35\ x\ 10^5\ J = (1794 J/K)(T)\\\\T = \frac{8.73\ x\ 10^5\ J}{1794\ J/K}[/tex]

T = 486.6 K

A hunter stood at about 60 m away from a tree. He used the bow to release the arrow in order to shoot a coconut held by a monkey in the tree. The coconut was at a height of 25 m from the ground. The hunter aimed directly at the coconut and the arrow left the bow at 45 m/s making an angle of 20 degree to the horizontal. At the moment thebhunter released the arrow, the monkey dropped the coconut such that it falls vertically from rest. Neglect air resistance and the arrow's size. What is the time taken for the arrow to hit the coconut?​

Answers

Answer:

[tex]v = u + at (upward)\\ 0 = 45 \sin(20) - 9.81t \\ t = 1.56s[/tex]

resistance question for physics!!!

Answers

Answer:

22

Explanation:

all the resistance numbers added together 2.0+6.0+10.0+4.0

resistance formula : v bettary = v1 + v2 + v3 ....

A car is sitting still what could cause the car to move

Answers

A force from another object maybe??

17. ____ Objects with more mass have
a. more gravity b. less gravity
c. more acceleration
d. less inerties

Answers

a. more gravity

This is the answer.

2 pts
The energy and penetrating power of nuclear radiation in decreasing order is:
Alpha > beta > gamma
Beta > alpha > gamma
Gamma > beta > alpha

Answers

Answer:

I think the answer 1

Explanation:

im probably wrong too i dont know

can you explain the three main important reason why we use machine​

Answers

Answer:

HERE IS YOUR ANSWER

Explanation:

1. The machines makes pur life easier.

2. It makes us do our works faster.

3. It does all the works that are harder for us.

Hope it helps you.

Explanation:  

First of all some do most of the work for us

Second, us humans are quite lazy

Third, it makes it quite easier in life

In a certain material, a beam of monochromatic light (f=5.09 × 10^14 Hz) has a speed of 2.04× 10^8 meters per second. The material could be
Question 14 options:

crown glass (n=1.52)


flint glass (n=1.66)


glycerol (n=1.47)


water (n=1.33)

Answers

Answer:

The Answer to question 14 is : glycerol (n=1.47)

The material should be considered as the glycerol (n=1.47).

Calculation of the material:

Since

a beam of monochromatic light (f=5.09 × 10^14 Hz) has a speed of 2.04× 10^8 meters per second.

Now the material should be

= 3*10^8 / 2.04× 10^8

= 1.47

Hence, The material should be considered as the glycerol (n=1.47).

Learn more about material here: https://brainly.com/question/19424938

A bmw 23 goes from 0 to 60 miles per hour in 5 seconds . It is also used in the second law of motion

Answers

Answer:

Acceleration = 5.3645 m/s²

Explanation:

Given the following data;

Initial velocity, u = 0mph

Final velocity, v = 60 mph

Time, t = 5 seconds

To find the acceleration (also used in the second law of motion), we would use the following formula;

A = (v - u)/t

Conversion:

Miles per hour to meters per seconds;

0 mph = 0 mps

1 mph = 0.44704 mps

60 mph = 60 * 0.44704 = 26.8224 mps

Next, we find the acceleration;

Acceleration = (26.8224 - 0)/5

Acceleration = 26.8224/5

Acceleration = 5.3645 m/s²

When placed at a certain point, a
0.110 C charge feels an electric
force of 19.8 N. What is the
magnitude of the electric field at
that point?

Answers

Answer: 180

Explanation: Acellus

This equation gives the magnitude of the electric field generated by a point charge Q. The distance r in the denominator is the separation between the point of interest and the point charge Q. Or the center of a spherical charge.

What magnitude of the electric field at that point?

It is simple to determine the size of the electric field by calculating the force per charge on the test charge. From this definition, the common metric units for electric field strength are derived. Electric field units would be force units divided by charge units, as the definition of an electric field is a force per charge.

F = |qvBsin()| calculates the magnetic force's magnitude. The following factors are involved in determining the force's direction. A plane is first defined by the magnetic field vector, B, and the velocity vector, v. In or out of this plane, the magnetic force is perpendicular to it.

Therefore, The electric force F, or Coulomb force, exerted per unit positive electric charge q at that place can be used to determine an electric field's strength, or E = F/q.

Learn more about electric fields here:

https://brainly.com/question/15800304

#SPJ2

A middle-A tuning fork vibrates with a frequency f of 440 hertz (cycles per second). You strike a middle-A tuning fork with a force that produces a maximum pressure of 5 pascals. Write a sine model that gives the pressure P as a function of the time t (in seconds).A middle-A tuning fork vibrates with a frequency f of 440 hertz (cycles per second). You strike a middle-A tuning fork with a force that produces a maximum pressure of 5 pascals. Write a sine model that gives the pressure P as a function of the time t (in seconds).

Answers

Answer:

P = 5sin(880πt)

Explanation:

We write the pressure in the form P = Asin2πft where A = amplitude of pressure, f = frequency of vibration and t = time.

Now, striking the middle-A tuning fork with a force that produces a maximum pressure of 5 pascals implies A = 5 Pa.

Also, the frequency of vibration is 440 hertz. So, f = 440Hz

Thus, P = Asin2πft

P = 5sin2π(440)t

P = 5sin(880πt)

a simple pendulum is hollow from within and its time period is T. how is the time period of pendulum affected when:
a) ¼ of Bob is filled with mercury
b)¾ of Bob is filled with Mercury
c) the bob is completely filled with Mercury

Answers

The period of a pendulum is independent of the mass of the bob so whether it's empty or filled with something, the period remains the same.

[tex]period = 2\pi \sqrt{ \frac{length}{g} } [/tex]

Two asteroids are located a certain distance away from each other. They have the same mass . The gravitational force of attraction is f . If the mass of one of the asteroids is doubled, how will the gravitational force be affected

Answers

Answer:

F' = 2F

Explanation:

The gravitational force of attraction between asteroids is given by Newton's Law of Gravitation:

[tex]F = \frac{Gm_1m_2}{r^2}[/tex]

where,

F = Force

G = Universal Gravitational Constant

m₁ = m₂ = m = mass of each asteroid

r = distance between asteroids

Therefore,

[tex]F = \frac{Gm^2}{r^2}[/tex]   --------------------- eq(1)

Now, if we double the mass of one asteroid:

[tex]F' = \frac{G(2m^2)}{r^2} \\\\F' = 2\frac{Gm^2}{r^2}[/tex]

using equation (1):

F' = 2F

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