How bullet train and a circuit breaker work on the magnet effect of current

Answer:

focal length=12cm

Explanation:

object size is equal to 1.00cm

object distance = 18cm

heigh of image = 2.00cm

image distance = ??

but magnification is given by;

M = 2.00/1.00 = 2

but u/v = M

u/18 = 2

u = 36

1/f = 1/u+1/v

1/f = 1/18+ 1/36

1/f = 1/12

f = 12cm

Answer:

C. both a speed and a direction

Answer:

A binary star is a star system consisting of two stars orbiting around their common barycenter.

#keep learning

Answer:

The speed of the train before and after slowing down is 22.12 m/s and 11.06 m/s, respectively.

Explanation:

We can calculate the speed of the train using the Doppler equation:

[tex] f = f_{0}\frac{v + v_{o}}{v - v_{s}} [/tex]        

Where:

f₀: is the emitted frequency

f: is the frequency heard by the observer  

v: is the speed of the sound = 343 m/s

[tex] v_{o}[/tex]: is the speed of the observer = 0 (it is heard in the town)

[tex] v_{s}[/tex]: is the speed of the source =?

The frequency of the train before slowing down is given by:

[tex] f_{b} = f_{0}\frac{v}{v - v_{s_{b}}} [/tex]  (1)                  

Now, the frequency of the train after slowing down is:

[tex] f_{a} = f_{0}\frac{v}{v - v_{s_{a}}} [/tex]   (2)  

Dividing equation (1) by (2) we have:

[tex] \frac{f_{b}}{f_{a}} = \frac{f_{0}\frac{v}{v - v_{s_{b}}}}{f_{0}\frac{v}{v - v_{s_{a}}}} [/tex]

[tex] \frac{f_{b}}{f_{a}} = \frac{v - v_{s_{a}}}{v - v_{s_{b}}} [/tex]   (3)  

Also, we know that the speed of the train when it is slowing down is half the initial speed so:

[tex] v_{s_{b}} = 2v_{s_{a}} [/tex]     (4)

Now, by entering equation (4) into (3) we have:

[tex] \frac{f_{b}}{f_{a}} = \frac{v - v_{s_{a}}}{v - 2v_{s_{a}}} [/tex]  

[tex] \frac{300 Hz}{290 Hz} = \frac{343 m/s - v_{s_{a}}}{343 m/s - 2v_{s_{a}}} [/tex]

By solving the above equation for [tex]v_{s_{a}}[/tex] we can find the speed of the train after slowing down:

[tex] v_{s_{a}} = 11.06 m/s [/tex]

Finally, the speed of the train before slowing down is:

[tex] v_{s_{b}} = 11.06 m/s*2 = 22.12 m/s [/tex]

Therefore, the speed of the train before and after slowing down is 22.12 m/s and 11.06 m/s, respectively.                        

I hope it helps you!                                                        

Answer:

a)  T = 2838.6 N,  b)   W = 1003.2 J,  c) W = 6.22 10⁴ J,  d) W = 2.79 10³ J

e) v_f = 2.65  m / s

Explanation:

a) To find the tension of the cable let's use Newton's second law

        T - W = m a

         T = W + ma

        T = m (g + a)

let's calculate

        T = 285 (-9.8 - 0.160)

        T = 2838.6 N

b) net work is stress work minus weight work

        W = F d

        W = (T-W) d

        W = (m a) d

        W = (285 0.160) 22

        W = 1003.2 J

c) the work done by the cable

         W = T d cos 0

          W = 2838.6 22.0

          W = 6.22 10⁴ J

d) The work done by the weight

the displacement is upwards and the weight points downwards, so the angle is 180º

        W = F. d

         W = F d cos 180

         W = -285 22.0

         W = 2.79 10³ J

e) the final speed of the load. Let's use the relationship between work and the change in kinetic energy

         W = ΔK

as part of rest K₀ = 0

          W = ½ m v_f²

          v_f = [tex]\sqrt{ \frac{2W}{m} }[/tex]

          v_f = [tex]\sqrt{\frac{2 \ 1003.2}{285} }[/tex]

          v_f = 2.65  m / s

Answer:

◆ See the attachment photo.

◆ Don't forget to thanks

◆ Mark as brainlist.

Complete Question

A system consists of a disk of mass 2.0 kg and radius 50 cm upon which is mounted an annular cylinder of mass 1.0 kg with inner radius 20 cm and outer radius 30 cm (see below). The system rotates about an axis through the center of the disk and annular cylinder at 10 rev/s.

(a) What is the moment of inertia of the system

(b) What is its rotational kinetic energy? axis 50 cm 30 cm 20 cm

Answer:

a) [tex]M.I=0.32kg.m^2[/tex]

b) [tex]K.E=621.8J[/tex]

Explanation:

From the question we are told that:

Mass [tex]m=2.0kg[/tex]

Disk Radius [tex]r_d=50cm=0.5m[/tex]

Mass of annular cylinder [tex]M_c=1.0kg[/tex]

Inner Radius of cylinder [tex]R_i=20cm=0.2m[/tex]

Outer Radius of cylinder [tex]R_o=0.3m[/tex]

Angular  Velocity [tex]\omega=10rev/s=2 \pi*10=62.83[/tex]

Generally the equation for moment of inertia is mathematically given by

[tex]M.I=0.5M r_d^2+0.5M_c(R_i^2+R_o^2)[/tex]

[tex]M.I=0.5(2*0.50)^2)+0.5*1*(0.2^2+0.30^)[/tex]

[tex]M.I=0.32kg.m^2[/tex]

Generally the equation for Rotational Kinetic Energy  is mathematically given by

[tex]K.E=0.5M.I \omega^2[/tex]

[tex]K.E=0.5 *0.32*62.83[/tex]

[tex]K.E=621.8J[/tex]

Answer:

225,000 kilometers per second

Explanation:

Have a nice day

Please delete my answer. I made a mistake

Answer:

The mechanical energy lost due to friction is 2,424.5 J

Explanation:

Given;

mass of the child, m = 25 kg

intial velocity of the child, u = 0

final velocity of the child, v = 7.8 m/s

initial position of the child, h₁ = 21 m

final position of the child, h₂ = 8 m

Let the energy lost due to heat = ΔE

ΔE + ΔK.E  + ΔP.E = 0

ΔE  +   ¹/₂m(v² - u²)  +  mg(h₂ - h₁) = 0

ΔE   +   ¹/₂ x 25(7.8² - 0)    +   25 x 9.8(8 - 21) = 0

ΔE   +  760.5 J   - 3185 J =

ΔE   -  2,424.5 J = 0

ΔE = 2,424.5 J

Therefore, the mechanical energy lost due to friction is 2,424.5 J

Answer:

The right solution is "50200 days".

Explanation:

Given:

Calories intake,

= 6000 kcal,

or,

= [tex]2.52\times 10^7 \ J[/tex]

Force,

= 500 N

As we know,

⇒ [tex]Work \ done = Force\times distance[/tex]

Or,

⇒ [tex]distance = \frac{Work \ done}{Force}[/tex]

By putting the values, we get

                  [tex]=\frac{2.52\times 10^7}{500}[/tex]

                  [tex]=0.502\times 10^5[/tex]

                  [tex]=50200 \ m[/tex]

hence,

The number of days will be:

= [tex]\frac{50200}{1}[/tex]

= [tex]50200 \ days[/tex]

Answer:

An Object is positively charged if it has more Positive Electrons in that object

Answer:

The correct answer is "4000 J".

Explanation:

Given that,

Force,

= 200 N

Displacement,

= 20 m

Now,

The work done will be:

⇒ [tex]Work=Force\times displacement[/tex]

By putting the values, we get

              [tex]=200\times 20[/tex]

              [tex]=4000 \ J[/tex]

Answer:

The output electric power is 1338876 W.

Explanation:

Volume, V = 690 cubic meter

height, h = 220 mm = 0.22 m

efficiency = 90 %

time , t = 1 s

Let the mass is m.

m = volume x density  

m = 690 x 1000 = 690000 kg

The input power is

P = m g h = 690000 x 9.8 x 0.22 = 1497640 W

The electric power out put is

[tex]P' = 90 % of 1487640\\\\\\P' = 1338876 W[/tex]

Answer:

I’ll try my best!

Answer:

By measure the effective length and the time period of the pendulum.

Explanation:

Let the student take the oscillating pendulum at the planet.

He measure the time period of the pendulum  by using the stop watch or the ordinary watch.

Then measure the effective length of the pendulum which is the distance between the center of gravity of the bob and the point of suspension of the pendulum.

Now, use the formula of the time period of the pendulum,

[tex]T =2\pi\sqrt\frac{L}{g}[/tex]

Here, L is the effective length of the pendulum, g is the acceleration due to gravity at the planet and T is time period of the pendulum.  

By rearranging the terms, we get

[tex]T =2\pi\sqrt\frac{L}{g}\\\\T^{2}=4\pi^2\times\frac{L}{g}\\\\g =\frac{4\pi^2L}{T^2}[/tex]

Here, by substituting the values of L and T, the student get the value of acceleration due to gravity at that planet.

Explanation:

Energy input = F×d = (150 N)(5.5 m) = 825 J

Energy output = mgh = (66 kg)(9.8 m/s^2)(1.10 m) = 711 J

efficiency = [tex]\dfrac{\text{output}}{\text{input}}[/tex]×100% = 86.2%

Answer:

Answer:

a) [tex]\omega _1=7.56rev/s=>47.5rads/s[/tex]

b) [tex]a=30.7[/tex]

c) [tex]a=35.91[/tex]

Explanation:

From the question we are told that:

Initial angular velocity [tex]\omega _1=7.56rev/s=>47.5rads/s[/tex]

Initial Length [tex]L_1=0.600m[/tex]

Final angular velocity [tex]\omega _2=6.22rev/s=39rad/s[/tex]

Final Length [tex]L_2=0.900m[/tex]

a)

Generally the rotation with the greater speed is

[tex]\omega _1=7.56rev/s=>47.5rads/s[/tex]

b)

Generally the equation for centripetal acceleration at 8.16 is mathematically given by

[tex]a=\omega_1^2*L_1[/tex]

[tex]a=8.16 rev/s*0.6[/tex]

[tex]a=30.7[/tex]

c)

At 6.35 rev/s

[tex]a=6.35 rev/s*0.9[/tex]

[tex]a=35.91[/tex]

Answer:

a)  V = 45 10³ V, b) U = 4.59 J

Explanation:

a) The electric potential for a series of point charges is

         V = k ∑ [tex]\frac{q_i}{r_i}[/tex]

in this case point P is at a distance of 1 m from each charge, so the point is located perpendicular to the charges at its midpoint

         V = k ( [tex]\frac{q_1}{r} + \frac{q_2}{r}[/tex])

         V = 9 10⁹ (10 - 5/ 1) 10⁻⁶

         V = 45 10³ V

b) the potential energy is

           U = k (  [tex]\frac{q_1q}{r} + \frac{q_2q}{r} + \frac{q_1q_2}{r_2}[/tex] )

where r = 1m and r₂ is the distance between the two charges r₂ = 0.10 m

           U = 9 10⁹ (10 2 / 1 - 5 2/1 - 10 5 /0.10) 10⁻¹²

           U = 9 10⁻³  510

           U = 4.59 J

Answer:

[tex]v = \sqrt{\frac{2GM}{r} }[/tex]

The formula for escape velocity where:

G - Gravitational constant (9.81 etc.)

M - the mass of the object the escape should be made from

r - distance to the centre of that mass

Answer:

the law of conservation of energy.

Explanation:

An electric circuit can be defined as an interconnection of electrical components which creates a path for the flow of electric charge (electrons) due to a driving voltage.

Generally, an electric circuit consists of electrical components such as resistors, capacitors, battery, transistors, switches, inductors, etc.

In Physics, a point where at least three circuit paths (wires) meet is referred to as a junction.

The Kirchhoff’s circuit laws are two(2) equations first published by Gustav Kirchhoff in 1845.

Fundamentally, they address the conservation of energy and charge in the context of electrical circuits.

One of the laws known as Kirchoff's Current Law (KCL) deals with the principle of application of conserved energy in electrical circuits.

Kirchoff's Current Law (KCL) states that the sum of all currents entering a junction must equal the sum of all currents leaving the junction.

This simply means that the algebraic sum of currents in a network of conductors(wires) meeting at a point is equal to zero.

The Law of Conservation of Energy states that energy cannot be destroyed but can only be transformed or converted from one form to another.

This ultimately implies that, Kirchhoff's junction rule is a statement of the law of conservation of energy.

Answer:

c. kilometers and kilograms

Explanation:

If two units represent different things, like for example grams and joules, where the first one is a unit for mass, and the second one a unit for energy we can not add them together. (

Let's analyze each one of the given options:

a: grams and milligrams

both grams and milligrams are units of mass, so after the appropriate unit conversions, we can add them.

b: miles and kilometers

Both are units for distance, after the appropriate unit conversions, we can add them.

c: kilometers and kilograms

"Kilometer" is a unit for distance, and "kilogram" a unit for mass, we can not add distance and mass, so these two can not be added together.

d: centimeters and yards

Both are units of distance,  after the appropriate unit conversions, we can add them.

Then the only one that we can not add together is option c:  kilometers and kilograms

Answer: The correct option is C (kilometers and kilograms).

Explanation:

UNITS is the quantity of a constant magnitude which is used to measure the magnitudes of other quantities of the same nature. The magnitude of a physical quantity is expressed as, Physical quantity = (numerical value) × (unit). There are six basic units of measurement which includes:

--> metre (m) - unit of length.

--> kilograms (kg) - unit of mass.

--> second (s) - unit of time.

--> ampere (A) - unit of electrical current.

--> kelvin (K) - unit of temperature and

--> mole (mol) - unit of the amount of substance.

Mass is the quantity of matter present in a body which is constant and is measured in KILOGRAMMES or GRAMS. While position is the distance and direction of an object from a particular reference point which is known to vary and is measured in METERS OR KILOMETRES.

From the above definition, KILOGRAMMES is used to measure the magnitude of a different quantity from KILOMETERS and therefore should not be added up after conversation.

Answer:

So the answer is B. A is wrong because negative answer = deceleration

Answer:

M = 1.409 10¹⁴ kg

Explanation:

In this exercise we have that the prioress with a minimum speed can escape from the asteroid, therefore we can use the conservation of energy relation.

Starting point. When you drop the stone

         Em₀ = K + U

         Em₀ = ½ m v² - G m M / r

where M and r are the mass and radius of the asteroid

Final point. When the stone is too far from the asteroid

          Em_f = U = - G m M / R_f

as there is no friction, the energy is conserved

          Em₀ = Em_f

          ½ m v² - G m M / r = - G m M / R_f

          ½ v² = G M (1 / r - 1 /R_f)

indicate that for the speed of v = 45.7 m /s, the stone does not return to the asteroid so R_f = ∞

          ½ v² = G M (1 /r)

          M = [tex]\frac{v^2 r}{2G}[/tex]

let's calculate

          M = [tex]\frac{45.7^2 \ 9}{ 2 \ 6.67 \ 10^{-11}}[/tex]

          M = 1.409 10¹⁴ kg

Answer:

Ba đặc trưng sinh lí của âm là độ cao, độ to và âm sắc.

Explanation:

Answer:

wavelength=75.0

speed of sound(v)=350 .0m/s

frequency(f)=?

we know,

v=f*wavelengh

350.0 =f*750

f. =350/75

=4.667

pls mark me brainlest

Answer:

eqcubuohwehuuc

Explanation:

the the the the the the the the the the the the the the the the dhueirrjhrhjrirjrheh3jeiiruj fnrhfjjjrjrj fjfiirrjejrjejej jrkrjrjrjrjrjdjdjfjrhruriruru rjridjhwjjsjd