Define the term e.m.f

Answer:

 θ₁ = θ₂,    n₁ sin θ₁ = n₂ sin  θ₂

instruments can be built that concentrate light on a small surface

Explanation:

The two laws of optical geometry have been known for quite some time.

The law of reflection states that when a ray of light reaches a surface, the reflected ray comes out at the same angle as the incident ray.

       θ₁ = θ₂

The law of refraction establishes how the direction of a light ray changes when it stops from one transparent medium to another.

           n₁ sin θ₁ = n₂ sin  θ₂

With any of these laws, instruments can be built that concentrate light on a small surface, which allows the weak light from the flares to be concentrated and objects to be measured and seen.

Electromagnetic radiation in its entire spectrum has the same properties, which is why telescopes of visible, infrared, and microwave light. Radio telescope, gamma rays use the same principles of the law of reflection and refraction. The main change between each instrument is the materials and which they are built,

a reflecting telescope must be built with a reflective surface, for example for microwaves metal surfaces are used

For gamma ray telescope it is preferred to constrict refracting telescope, therefore the material must be transparent to gamma rays

The radio telescope uses reflection and the surface is metallic, sometimes to reduce the weight the surface has holes smaller than the length of the donut that you want to measure.

Answer:

i believe its temperate

Explanation:

The climate zone that has hot summers, cold winters, and average amounts of precipitation throughout the year is the temperate climate zone. So, option C is correct.

Climatic zones are defined as the areas that have different climatic conditions over the world.

Here,

The climate zone that hot summers, cold winters and average amounts of precipitation throughout the year is the temperate climate zone.

The temperate climate zones are the areas that have mild temperature condition that are located between the subtropical and the polar regions. These are zones with moderate rainfall that is throughout the year. The temperature in this zone will change greatly between the summer and winter seasons. These zones are hotter during the summer and very cold during the winter.

The temperate zone has an average precipitation of 800 mm.

Hence,

The climate zone that has hot summers, cold winters, and average amounts of precipitation throughout the year is the temperate climate zone.

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Answer:

The final speed of the crate is 12.07 m/s.

Explanation:

For the first 10.0 meters, the only force acting on the crate is 225 N, so we can calculate the acceleration as follows:

[tex] F = ma [/tex]

[tex] a = \frac{F}{m} = \frac{225 N}{51.0 kg} = 4.41 m/s^{2} [/tex]

Now, we can calculate the final speed of the crate at the end of 10.0 m:

[tex] v_{f}^{2} = v_{0}^{2} + 2ad_{1} [/tex]                  

[tex] v_{f} = \sqrt{0 + 2*4.41 m/s^{2}*10.0 m} = 9.39 m/s [/tex]    

For the next 10.5 meters we have frictional force:

[tex] F - F_{\mu} = ma [/tex]

[tex] F - \mu mg = ma [/tex]

So, the acceleration is:

[tex] a = \frac{F - \mu mg}{m} = \frac{225 N - 0.17*51.0 kg*9.81 m/s^{2}}{51.0 kg} = 2.74 m/s^{2} [/tex]

The final speed of the crate at the end of 10.0 m will be the initial speed of the following 10.5 meters, so:

[tex] v_{f}^{2} = v_{0}^{2} + 2ad_{2} [/tex]  

[tex] v_{f} = \sqrt{(9.39 m/s)^{2} + 2*2.74 m/s^{2}*10.5 m} = 12.07 m/s [/tex]  

Therefore, the final speed of the crate after being pulled these 20.5 meters is 12.07 m/s.  

I hope it helps you!                              

Explanation:

Pencil is clearly an opaque object because, we cannot see through it. For example, take a pencil in your front. You will observe that, you are not able to see the objects behind it. And that is why you can say that pencil is an opaque object.

Answer:

A pencil is opaque

Explanation:

A pencil is opaque, because light cannot pass through it and shadow is created.

Answer:

Solid sphere

Explanation:

According to the given situation, the solid sphere would contain the less moment of inertia because it would carry large mass that closed to the axis of rotation

Also if there is a less moment of inertia so there would be high angular acceleration under a torque

α = τ/I

So the solid sphere would reach a speed of 10 rad/s first

Answer:

300m/s

Explanation:

f = c/λ

f = frequency

c = speed

λ = wave length

f = c/λ

300 = c/1

c = 300m/s

Answer:

  [tex]\frac{T_x}{T_y} = 22.63[/tex]

Explanation:

Kepler's third law is an application of Newton's second law for circular motion

          T² = K a³

let's apply this expression for each satellite

satellite X

            Tₓ² = K aₓ³

satellite Y

            [tex]T_y^2 = K a_y^3[/tex]

 the relation of the periods is

          [tex]\frac{T_x}{T_y} = \sqrt{ (\frac{a_x}{a_y} )^3 }[/tex]

they indicate us

            aₓ = 8 a_y

substitutes

           [tex]\frac{T_x}{T_y} = 8^{3/2}[/tex]

           [tex]\frac{T_x}{T_y} = 22.63[/tex]

Answer:

e)  A changing magnetic field produces an electric field.

Explanation:

Ok, we start with a magnetic field and let's study how it affects the motion of a single electron. As the magnetic field changes, it will cause an electromotive force, that moves the electron, and because now we have a moving electron, now we will have an electric field. (Such that the direction of the electromotive force opposes the direction in which the magnetic field changes). This also can be deduced if we look at the third Maxwell's equation:

dE/dx = -dB/dt

This says that the spatial change in an electric field depends on how the magnetic field changes as time pass.

Then the correct option is e)  A changing magnetic field produces an electric field.

Answer: Sweetheart i'm not walking backward for an hour for your little assignment

Explanation: Do it yourself lazy! Have a great day!

Answer:

T

beacuse:

Energy can be transferred from one object to another by doing work. ... When work is done, energy is transferred from the agent to the object, which results in a change in the object's motion (more specifically, a change in the object's kinetic energy).

Answer:

It is the force that pulls down an object on the air

Answer: a downward pull on any object

Explanation:

Answer:

(i) 100 m/s²

(ii) 450 m

Explanation:

From the question,

Using,

(i) a = (v-u)/t................. Equation 1

Where a = acceleration of the drone, v = final velocity of the drone, u = Initial velocity of the drone, t = time.

Given: v = 300 m/s, u = 0 m/s (from rest), t = 3 s

Substitute these values into equation 1

a = (300-0)/3

a = 300/3

a = 100 m/s²

Hence the acceleration of the drone is 100 m/s²

(ii) using,

s = ut+at²/2.................... Equation 2

Where s = distance traveled by the drone.

also substitute the values above into equation 2

s = 0(3)+100(3²)/2

s = 50×9

s = 450 m

Answer:

20000

Explanation:

Speed = Wavelength x Wave Frequency. In this equation, wavelength is measured in meters and frequency is measured in hertz (Hz), or number of waves per second. Therefore, wave speed is given in meters per second, which is the SI unit for speed.

Answer:

[tex]0.886[/tex] N buoyant force is exerted by air

Explanation:

My weight is [tex]75[/tex] Kg

Weight = mass * gravity

As we know

Buoyant Force is equal to the product of density * acceleration due to gravity and volume of the body

Assuming weight density is a bit less than that of water or equal to water i.e [tex]997.77[/tex] kg/m3

Volume is equal to mass / density

[tex]= 75[/tex] Kg * g/[tex]997.777[/tex]

[tex]= 0.0751[/tex] * g

Buoyant Force

= Volume * g * density

[tex]= 0.0751 * 9.8 * 1.2041[/tex]kg/m3

[tex]= 0.886[/tex] N

Answer:

Explanation:

From the given information:

Let the first weight be [tex]m_ 1[/tex] = 80 kg

The weight of the buddy be [tex]m_2[/tex] = 120 kg

The weight of  Bubba be [tex]m_3[/tex] = 60 kg

Also, since you and Budda are a distance of 4m to each other, then the length to which both meet buddy will be:

[tex]x_1 = x_3 = \dfrac{4}{2} \\ \\ = 2[/tex]

The length of the boat be [tex]x_2[/tex] = 4 m

∴

We can find the center of mass of the system by using the formula:

[tex]X_{CM} = \dfrac{m_1x_1+m_2x_2+m_3x_3}{m_1+m_2+m_3} \\ \\ X_{CM} = \dfrac{(80 \times 2)+(120\times4)+(60\times2)}{80+120+60} \\ \\ X_{CM} = \dfrac{160+480+120}{260} \\ \\ \mathbf{X_{CM} = 2.923}[/tex]

Answer: 1.  walking across a carpet and touching a metal door handle            2. pulling your hat off and having your hair stand on end.

Explanation

:)

Answer:

1 astronomical unit, or AU, is the average distance from the Earth to the Sun; that's about 150 million km. So, Neptune's average distance from the Sun is 30.1 AU. Its perihelion is 29.8 AU, and it's aphelion is 30.4 AU.

Short Answer: it is 29

Explanation:

sorry if its wrong

Answer:

29

Explanation:

I just took a test! not only that but the other person who answered this question had the corrected answer.

Answer:

car B will be 30 Km ahead of car A.

Explanation:

We'll begin by calculating the distance travelled by each car. This is illustrated below:

For car A:

Speed = 40 km/h

Time = 3 hours

Distance =?

Speed = distance / time

40 = distance / 3

Cross multiply

Distance = 40 × 3

Distance = 120 Km

For car B:

Speed = 50 km/h

Time = 3 hours

Distance =?

Speed = distance / time

50 = distance / 3

Cross multiply

Distance = 50 × 3

Distance = 150 Km

Finally, we shall determine the distance between car B an car A. This can be obtained as follow:

Distance travelled by car B (D₆) = 150 Km

Distance travelled by car A (Dₐ) = 120 Km

Distance apart =?

Distance apart = D₆ – Dₐ

Distance apart = 150 – 120

Distance apart = 30 Km

Therefore, car B will be 30 Km ahead of car A.

Answer:

a)=46.49 m

b)=0.861 m/s

c)=0.274 m/s

Explanation:

I am quite confuse with ans C . If it is correct but I can explain .lol

Answer:

he maximum frequency occurs when the denominator is minimum

 f’= f₀  [tex]\frac{343}{343 + v_s}[/tex]

Explanation:

This is a doppler effect exercise, where the sound source is moving

           f = fo [tex]\frac{v}{v-v)s}[/tex]      when the source moves towards the observer

           f ’=f_o  [tex]\frac{v}{v+v_{sy}}[/tex]  Alexandrian source of the observer

the maximum frequency occurs when the denominator is minimum, for both it is the point of maximum approach of the two objects

          f’= f₀  [tex]\frac{343}{343 + v_s}[/tex]

Answer:

I = 3.81 x 10⁴ A

Explanation:

The magnetic field of a solenoid must be equal to the field of earth:

[tex]Field\ of\ Earth = Field\ of\ Solenoid\\52\ T = \mu n I\\I = \frac{52}{\mu n}[/tex]

where,

I = current passing through solenoid = ?

μ = permeability of free space = 4π x 10⁻⁷ N/A²

n = no. of turns per unit length = [tex]\frac{5000\ turns}{4.6\ m}[/tex] = 1086.96 /m

Therefore,

[tex]I = \frac{52\ T}{(4\pi\ x\ 10^{-7}\ N/A^2)(1086.96\ /m)}[/tex]

I = 3.81 x 10⁴ A

Answer:

J = 3.564 N.s

Explanation:

From  the given information:

angle θ = 27°

mass = 0.0200 kg

speed = 33.0 m/s

To determine the impulse applied using the equation:

J = m(2V cos  θ)

J = 0.0200 (2 × cos (27.0))

J = 0.0200 (2 × 0.8910)

J = 0.03564

J = 3.564 N.s

Answer:

No, it is not a good assumption

Explanation:

From the given information:

The work Jessie did was quite more than the work done by the force of gravity. This is because the gravity of the force on her body is perpendicular to its motion and the work done by Jessie is due to the muscular force of her body. Hence, the total power she produced is more than the calculated amount.

Answer:

- After throwing the snow, velocity of the thrower is 2.33 m/s

- the velocity of the receiver is 0.026 m/s

Explanation:

Given the data in the question;

Using conservation of momentum,

Initial thrower has a momentum of mv; [tex]m_{total[/tex]v

(69.5 kg + 0.0475 kg) × 2.35 m/s = 163.4366 kg.m/s

Now, When he throws it at 31.5 m/s, these constitutes a momentum of;

(0.0475 kg )(31.5 m/s) = 1.49625 kg.m/s

hence his momentum now is: 163.4366 - 1.49625 = 161.94035 kg.m/s

To get his velocity, we say;

161.94035 = mv

{ he lost weight of the snow ball so, m = 69.5 kg )

161.94035 = 69.5 × v

v = 161.94035 / 69.5

v = 2.33 m/s

Therefore, After throwing the snow, velocity of the thrower is 2.33 m/s

Next is the Receiver;

the receiver will gain momentum of 1.49625 kg.m/s

he has no momentum initially and after he catches the snow ball;

1.49625 kg.m/s = mv

1.49625 kg.m/s = ( 57.5 kg +  0.0475 kg ) × v

1.49625 kg.m/s = 57.5475 kg × v

v = ( 1.49625 kg.m/s ) / 57.5475 kg

v = 0.026 m/s

Therefore, the velocity of the receiver is 0.026 m/s

Answer:

the wavelength of the light is 6.313 × 10⁻⁷ m

Explanation:

Given the data in the question;

for a double slit interference;

θ = nλ/d

for adjacent lines

θ = λ/d

and d = 0.33 mm = 0.00033 m

and θ = 0.44 × 10⁻² m / 2.30 m

so

λ = θ × d

λ = ( 0.44 × 10⁻² m / 2.30 m ) × 0.00033 m

λ  = 0.001913043478 × 0.00033 m

λ =  6.313 × 10⁻⁷ m

Therefore, the wavelength of the light is 6.313 × 10⁻⁷ m

Answer:

Their different wavelengths.

Explanation:

trust me

All EM waves (light waves) travel at the same speed through the vacuum of space. If the different types of waves are distinguished by their frequency, the basic characteristic of the waves that determine their difference is the wavelength of the electromagnetic waves.

It can be understood in terms of the distance between any two similar successive points across any wave for example wavelength can be calculated by measuring the distance between any two successive crests.

It is the total length of the wave for which it completes one cycle.

The wavelength is inversely proportional to the frequency of the wave as from the following relation.

C = νλ

where c is the speed of light

ν is the frequency of the wave

λ is the wavelength of the wave

As we know electromagnetic waves (light waves) travel at the same speed through the vacuum of space which is the speed of light which is 3×10⁸ meter/second

All EM waves (light waves) travel at the same speed through the vacuum of space. If the different types of waves are distinguished by their frequency, the basic characteristic of the waves that determine their difference is the wavelength of the electromagnetic waves.

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Answer:

the speed of the textbook just before it hits the floor is 2.4 m/s

Explanation:

  Given the data in the question;

mass of pulley = 1.50 kg

radius of pulley = 0.240 m

mass of text book = 2.0 kg

height from which text book was released = 0.9 m

angular speed of the pulley = 10.0 rad/s

the speed of the textbook just before it hits the floor = ?

the speed of the textbook v = angular speed of the pulley × radius of pulley

we substitute

v = 10.0 rad/s × 0.240 m

v = 2.4 m/s

Therefore, the speed of the textbook just before it hits the floor is 2.4 m/s