A bike travels 15.0 km in 45.0 min. Its average speed in km/h is .

Answer:

Explanation:

Emf e generated in a coil with no of turn n and area A rotating in a magnetic field B  with angular speed of ω is given by the expression

e = e₀ sinωt

where e₀ = nωAB which is the maximum emf generated

Putting the given values

15.7 = 1000xω x 20 x 10⁻² x 5

ω = .0157

frequency of rotation

= ω / 2π

= .0157 / 2 x 3.14

= .0025 /s

9 rotation / hour .

Answer:

The initial velocity is 38.46 m/s.

Explanation:

The horizontal distance travel by the tennis ball = 13 m  

The height at which the tennis ball dropped = 56 cm

Now calculate the initial speed of tennis ball.

The vertical velocity is zero.

Below is the calculation. Here, first convert centimetre into kilometre. So, height at which ball dropped is 0.56 km.

[tex]v = \sqrt{2 \times 9.8 \times 0.56} = 3.32 m/s \\[/tex]

[tex]t = \frac{3.32}{9.8} = 0.338s \\[/tex]

[tex]Ux \times t = 13 \\[/tex]

[tex]Ux = \frac{13}{0.338} = 38.46 m/s = Initial velocity.[/tex]

Answer:

0.00091

Explanation:

(9x10^9) (2.6x10^-6) (1.4x10^-6) / 36

(9,000,000,000) (0.0000026) (0.0000014) /36

|

23,400(0.0000014) /36

|

0.03276 /36

|

0.00091

Answer:

(C) is correct option.

Explanation:

The loudness of sound wave determines its amplitude. If the sound is loud, it will have more amplitude while if the sound is soft, it will have less amplitude.

On doubling the amplitude of sound wave, it will become more loud.

Doubling the amplitude of a sound wave will leave the speed of sound unchanged, but cause the sound to be louder. Hence, the correct option is (C).

Answer:

C. is always perpendicular to the surface of the conductor

Explanation:

On a charged conductor , electric charge is uniformly distributed on its surface . The lines of forces are also uniformly  distributed on all directions . They repel each other so they emerge perpendicular to the surface so that they do nor cut each other and at the same time they remain at maximum distance from each other.

Answer:

a:it speed up

b:it should be positive since final

velocity is larger than initial velocity

c:acceleration is approximately 4.5

m/s^2

Explanation:

initial velocity=u=4.47m/s

Final velocity=v=17.9m/s

Time=t=3 seconds

a:the car speed up since the velocity

increased

b:change in velocity is positive

because final velocity is larger than

initial velocity

17.9-4.47=13.43 m/s

c: acceleration=(v-u)/t

acceleration=(17.9-4.47)/3

acceleration=13.43/3

acceleration=4.5 m/s^2

If a car goes from a velocity u to a velocity v, the change in velocity is expressed as;

[tex]\triangle v =v-u[/tex]

Given

final velocity v = 17.9m/s

initial velocity u = 4.47m/s

[tex]\triangle v = 17.9-4.47\\\triangle v =13.43m/s[/tex]

a) Since the change in velocity is a positive value, this shows that the car speeds up.

b) The answer should be positive since the final velocity is greater than the initial velocity.

c) Acceleration is the change in velocity with respect to time

[tex]a=\frac{v-u}{t}\\a=\frac{17.9-4.47}{3} \\a=\frac{13.43}{3}\\a= 4.48m/s^2[/tex]

Hence the acceleration of the car is 4.48m/s²

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Answer:

a) Beth will reach before Alan

b)Beth has to wait 20 min for Alan to arrive

Explanation:

let 'd' be distance b/w Los Angeles and San  Francisco i.e 400 mi

considering ,

Alan's speed [tex]v_A[/tex]=50mph

Beth's speed [tex]v_B[/tex]=60mph

->For Alan:

The time required [tex]t_A[/tex]= d/[tex]v_A[/tex]= 400/50 => 8h

-> For beth:

The time required [tex]t_B=\frac{d}{v_B} =\frac{400}{60} =>6\frac{2}{3} h[/tex] => 6h 40m

Alan will reach at 8:00 a.m +8h = 4:00p.m.

Beth will reach at 9:00 a.m +6h 40m= 3:40p.m.

a) Beth will reach before Alan

b)Beth has to wait 20 min for Alan to arrive

Answer:

D. Terrance

Explanation:

This is because he is seeing things that aren't there.

Dominique has amnesia (useless it's just like an existential crisis)

Jasmine is having delusions? but she's not hallucinating.

Damion has I guess temporary amnesia? Maybe brain damage? but not hallucinations.

Answer:

as in motor generaror are connected to same shaft then both machines are working with same speed

but number of poles are different with same speed means both machines are working with different frequencies

we know

frequency F = N*P/120

speed N = 82120F/P

given

motor speed = generator speed

120F1/P1 = 120F2/P2

F1/P1 = F2/P2

output frequency is 25 which is obtained from generator so F2=25

input frequency is 60 which is given to motor soF1=60

60/P1 = 25/P2

60/25 = P!/P2

P1/P2 = 12/5

multiply and divided by 2 becuase poles are even

P1/P2 = 12*2/5*2

=24/10

P1= 24 poles a

P2 =10 poles we get 25 hz frequency from 60 hz frequency

Answer:

33.2 m

Explanation:

For the first object:

y₀ = 81.5 m

v₀ = 0 m/s

a = -9.8 m/s²

t₀ = 0 s

y = y₀ + v₀ t + ½ at²

y = 81.5 − 4.9t²

For the second object:

y₀ = 0 m

v₀ = 40.0 m/s

a = -9.8 m/s²

t₀ = 2.20 s

y = y₀ + v₀ t + ½ at²

y = 40(t−2.2) − 4.9(t−2.2)²

When they meet:

81.5 − 4.9t² = 40(t−2.2) − 4.9(t−2.2)²

81.5 − 4.9t² = 40t − 88 − 4.9 (t² − 4.4t + 4.84)

81.5 − 4.9t² = 40t − 88 − 4.9t² + 21.56t − 23.716

81.5 = 61.56t − 111.716

193.216 = 61.56t

t = 3.139

The position at that time is:

y = 81.5 − 4.9(3.139)²

y = 33.2

Answer:

Magnetic fields point from the north pole to the south pole of a magnet.

An example of the Biot-Savart law is the effect of the earth's maghytic field on the electron rays coming from the sun.

The north pole of a magnet will be attracted to the south pole of the earth.

If a bar magnet is cut in half two magnets with like poles will be created

Explanation:

The magnetic field of Earth is due to the presence of iron in the core of the Earth.  

The metal emits the magnetic waves from it and the North and South pole of the planet.

Both the poles emit the magnetic rays which create magnetic sheet around it. The Earth acts like a magnet bar if which is cut into two half, the planet will act like two magnets. Also, Biot Savarts's law states that the magnetic field does not affect the electron rays coming from the Sun.

Thus, the selected options are correct.

Answer:

ACDE

Explanation:

Answer:

Explanation:

The mass of cube = 700 kg

volume = 1 m³

density = 700 kg / m²

Its density is less than that of water so it will try to float on the surface .

Tension in rope will be equal to net upward force

upthrust = volume x density of water x g

= 1 x 10³ x 9.8

= 9800 N

weight of cube = mass x g

= 700 x 9.8

= 6860 N .

Net upward force = 9800 - 6860

= 2940 N.

Tension in the rope = 2940 N.

Rope will hold the cube inside and not allow it to go outside water .

b )

If rope is cut , cube being lighter , will float on surface of water .

Part of cube inside water while floating

= 6860 / 9800

= .7

.7 m will remain inside water

part floating outside

= 1 - 0.7

= 0.3 m .

Answer:

The deceleration is  [tex]a = - 76.27 m/s^2[/tex]

Explanation:

From the question we are told that

   The height above  firefighter safety net is [tex]H = 14 \ m[/tex]

   The length by which the net is stretched is [tex]s = 1.8 \ m[/tex]

From the law of energy conservation

    [tex]KE_T + PE_T = KE_B + PE_B[/tex]

 Where [tex]KE_T[/tex] is the kinetic energy of the person before jumping which equal to zero(because to kinetic energy at maximum height )

   and  [tex]PE_T[/tex] is the potential energy of the before jumping  which is mathematically represented at

          [tex]PE_T = mg H[/tex]

and  [tex]KE_B[/tex] is the kinetic energy of the person just before landing on the safety net  which is mathematically represented at

        [tex]KE_B = \frac{1}{2} m v^2[/tex]

and  [tex]PE_B[/tex] is the potential energy of the person as he lands on the safety net which has a value of zero (because it is converted to kinetic energy )

   So the above equation becomes

          [tex]mgH = \frac{1}{2} m v^2[/tex]

=>           [tex]v = \sqrt{2 gH }[/tex]

    substituting values

                [tex]v = 16.57 m/s[/tex]

Applying the equation o motion

             [tex]v_f = v + 2 a s[/tex]

Now the final velocity is zero because the person comes to rest

      So

         [tex]0 = 16.57 + 2 * a * 1.8[/tex]

            [tex]a = - \frac{16.57^2 }{2 * 1.8}[/tex]

            [tex]a = - 76.27 m/s^2[/tex]

Answer:

......................

Answer:

b) The electric potential of the larger sphere is the same as that of the smaller sphere

Explanation:

An electric potential is the amount of work needed to move a unit of charge from a reference point to a specific point inside the field without producing an acceleration. The reference point is typically the Earth or a point at infinity, although any point can be used.

It is proportional to the charge on a particle and inversely proportional to its relative distance to the electric field.

E = kQ/r

Where k = 1/4¶E°

Where E° is permittivity of free space 8.85x10^-12 F/m

Answer:

Minority group - People who are singled  out for unequal treatment  and who regard  themselves as objects of  collective discrimination.

Ethnicity - A shared identity based on  cultural elements such as  heritage, language, and  religion.

Majority group - A group's subset that  consists of more than half  of the entire group's  members.

Race - A socially constructed  group of people who share  physical characteristics  that are considered  significant by a society  and that are used to  distinguish them from  other groups.

Explanation:

To better understand the above-mentioned definitions we would use some examples:

Elder people can be considered as a minority group in the United States because of their reduced status as a consequence of popular discrimination and prejudice against them. In contrast to them, young men consisting of more than half the population in the age category is an example of the majority group.

Groups of people like Hispanic Americans, Jews, Italian America, Irish are some examples of people belonging to different ethnic backgrounds residing in the U.S.

African Americans who are distinguished based on their skin color is an example of race.

Answer:

A fan pushes hot air out of a vent and into a room. The hot air displaces cold air in the room, causing the cold air to move closer to the floor.

The hot air displacing the cold air is an example of  transfer by

Explanation:

Answer:30N

Explanation:

Mass=5kg

Acceleration=6m/s^2

Force=mass x acceleration

Force=5 x 6

Force=30N

Answer:

30n

Explanation:

Mass=5kg

Acceleration=6m/s^2

Force=mass x acceleration

Force=5 x 6

Force=30N

Answer:

Explanation:

Problem relates to diffraction of light . Location for 2 nd diffraction minima is

[tex]x=2\times\frac{\lambda D}{d}[/tex]  where λ is wavelength of light , D is distance of screen , d is slit width .

Puting the values

[tex]x=2\times\frac{620D}{d}[/tex]

for unknown wavelength , position of third diffraction is

[tex]x=3\times\frac{\lambda D}{d}[/tex]

from these two equations

[tex]x=2\times\frac{620D}{d}[/tex][tex]=3\times\frac{\lambda D}{d}[/tex]

λ = 413.33 nm .

Answer:

(a) Ra = 9.25 kN; Rb = 5.75 kN

(b) 26.7 kN

Explanation:

(a) Draw a free-body diagram of the crane.  There are four forces:

Reaction Ra pushing up at A,

Reaction Rb pushing up at B,

Weight force 12.5 kN pulling down at G,

and weight force 2.5 kN pulling down at F.

Sum of moments about B in the counterclockwise direction:

∑τ = Iα

-Ra (0.66 m + 0.42 m + 2.52 m) + 12.5 kN (2.52 m + 0.42 m) − 2.5 kN ((3.6 m + 0.9 m) cos 30° − 2.52 m) = 0

-Ra (3.6 m) + 12.5 kN (2.94 m) − 2.5 kN (1.38 m) = 0

Ra = 9.25 kN

Sum of moments about A in the counterclockwise direction:

∑τ = Iα

Rb (0.66 m + 0.42 m + 2.52 m) − 12.5 kN (0.66 m) − 2.5 kN ((3.6 m + 0.9 m) cos 30° + 0.66 m + 0.42 m) = 0

Rb (3.6 m) − 12.5 kN (0.66 m) − 2.5 kN (4.98 m) = 0

Rb = 5.75 kN

Alternatively, you can use sum of the forces in the y direction as your second equation.

∑F = ma

Ra + Rb − 12.5 kN − 2.5 kN = 0

Ra + Rb = 15 kN

9.25 kN + Rb = 15 kN

Rb = 5.75 kN

However, you must be careful.  If you make a mistake in the first equation, it will carry over to this equation.

(b) At the maximum weight, Ra = 0.

Sum of the moments about B in the counterclockwise direction:

∑τ = Iα

12.5 kN (2.52 m + 0.42 m) − F ((3.6 m + 0.9 m) cos 30° − 2.52 m) = 0

12.5 kN (2.94 m) − F (1.38 m) = 0

F = 26.7 kN

Answer:

3) False. It is expensive since it requires sophisticated equipment and very low temperatures

Explanation:

Nuclear magnetic resonance imaging measurements consist of magnetic resonance imaging to analyze tissues by the transition of the unpaired electron at carbon 13, giving information on the structure and composition of tissues. This information is processed in computers and transformed into images.

So the physical measurement is the MRN

Now we can analyze the statements in the problem

1) True by itself a magnetic measurement is non-invasive

2) True. Measuring carbon transitions has information about the soft tissue of the body

3) False. It is expensive since it requires sophisticated equipment and very low temperatures

4) Right. The applied magnetic field is high to be able to induce carbon transaction

Answer:

true. b, c and d

Explanation:

Let's review each statement separately  

a) False. The kinematics studies the position, speed and acceleration of the bodies, but not what causes these changes

b) True. Velocity is the displacement between time, displacement is a vector, and time is a scalar, so the division between them gives a vector

c) True. speed is the displacement that is a length between time, so its unit is length / time

d) true  desaceleration = - aceleration

Answer:

The velocity just before hitting the ground is [tex]v_f = 30 m/s[/tex]

Explanation:

From the question we are told that

    The initial speed is  [tex]u = 10 m/s[/tex]

    The final speed is  [tex]v = 30 \ m/s[/tex]

From the equations of motion we have that

      [tex]v^2 =u^2 + 2as[/tex]

Where s is the distance travelled which is the height of the cliff

  So making it the subject of the the formula  we have that

        [tex]s = \frac{v^2 - u^2 }{2a}[/tex]

Where a is the acceleration due to gravity with a value  [tex]a = 9.8m/s^2[/tex]

       So

                  [tex]s = \frac{30^2 - 10^2 }{2 * 9.8 }[/tex]

                  [tex]s = 40.8 \ m[/tex]

Now we are told that was through horizontally with a speed of

      [tex]v_x =10 m/s[/tex]

Which implies that this would be its velocity horizontally through out the motion

    Now it final  velocity vertically can be mathematically evaluated as

            [tex]v_y = \sqrt{2as}[/tex]

Substituting values

             [tex]v_y = \sqrt{(2 * 9.8 * 40.8)}[/tex]

             [tex]v_y = 28.3 \ m/s[/tex]

The resultant final velocity is mathematically evaluated as

       [tex]v_f = \sqrt{v_x^2 + v_y^2}[/tex]

Substituting values

       [tex]v_f = \sqrt{10^2 + 28.3^2}[/tex]

       [tex]v_f = 30 m/s[/tex]

I think the answer is A

Answer:

A fan pushes hot air out of a vent and into a room. The hot air displaces cold air in the room, causing the cold air to move closer to the floor.

The hot air displacing the cold air is an example of  transfer by

Explanation:

also the answer is hit my dm on ig

Answer: B. 9032°F

Explanation:

First we take down the data made available to us.

Estimated temperature of the Earth's core = 5000° Celsius

Now to express this temperature in Fahrenheit, we make use of the formula;

[°F] = [°C] × 9/5 + 32

Where

[°F] is temperature in Fahrenheit and

[°C] is temperature in Celsius

So we just input our figure into the formula

[°F] = [5000°] × 9/5 + 32

°F = 5000 × 1.8 + 32

°F = 9000 + 32

°F = 9032°

So 5000° Celsius is expressed as 9032° Fahrenheit

Answer:

The answer is diffraction

Explanation:

Answer:

The answer is diffraction

Explanation:

I did the test! HOPE THIS HELPS!

Here are a list of items I found.

some brushes

a armature

a permanent magnet

some slip rings

Answer:

A fan pushes hot air out of a vent and into a room. The hot air displaces cold air in the room, causing the cold air to move closer to the floor.

The hot air displacing the cold air is an example of  transfer by

Explanation:

Answer:

The volume of gas in an early diving bell full of air at sea level is halved at 10 m according to Boyle’s law

Explanation:

;at 20 m pressure is 300 kPa absolute and the gas is compressed into one third the volume.

HOPE THIS HELPS         i did this before

Answer:

C

Explanation:

Cereal made with refined grains is the healthiest type of carbohydrate.

A carbohydrate is defined as a bio-molecule which consists of carbon,hydrogen and oxygen atoms which are usually in the ratio of 2:1 with the empirical formula C[tex]_n[/tex](H₂O)[tex]_n[/tex].

This term is most commonly used in  field of biochemistry as a synonym of saccharide which is a group of sugars, starch and cellulose.

They perform various functions in living organisms. They serve as an energy source and as well as structural components . They are a key component in providing nutrition and are found in wide variety of natural as well as processed foods.

Carbohydrates occur as cellulose in the cell walls of plants and is one of the components of insoluble dietary fibers.

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