Use Kepler's third law to determine how many days it takes a spacecraft to travel in an elliptical orbit from a point 6 965 km from the Earth's center to the Moon, 385 000 km from the Earth's center.

Answer:

acting force is the answer

The direction of the magnetic force on the moving electron is upward.

The direction of the magnetic force on the electron can be determined by applying right hand rule.

This rule states that when the thumb is held perpendicular to the fingers, the thumb will point in the direction of the speed while the fingers will point in the direction of the field and the magnetic force will be perpendicular to the field.

Thus, we can conclude that, the direction of the magnetic force on the moving electron is upward.

Learn more here:https://brainly.com/question/14434299

Answer:

The wave is traveling in the y axis direction

Explanation:

Because the wave will always travel in a direction 90° to the magnetic and electric components

Explanation:

It is given that,

The separation between two parallel wires, r = 11 cm = 0.11 m

Current in wire 1, [tex]q_1=54\ A[/tex]

Current in wire 2, [tex]q_2=45\ A[/tex]

Length of wires, l = 4.3 m

We need to find the magnitude of the magnetic force on a 4.3 m length of the wire carrying the greater current. The magnetic force per unit length is given by :

[tex]\dfrac{F}{l}=\dfrac{\mu_o I_1I_2}{2\pi r}\\\\F=\dfrac{\mu_o I_1I_2l}{2\pi r}\\\\F=\dfrac{4\pi \times 10^{-7}\times 54\times 45\times 4.3}{2\pi \times 0.11}\\\\F=0.0189\ N[/tex]

So, the magnetic force on a 4.3 m length of the wire  on both of currents is F=0.0189 N.

Explanation:

It is given that,

Speed of bus 1 is 36 km/h and speed of bus 2 is 108 km/h. We need to find the distance between bus 1 and 2 after 20 minutes.

Time = 20 minutes = [tex]\dfrac{20}{60}\ h=\dfrac{1}{3}\ h[/tex]

As the buses are moving in opposite direction, then the concept of relative velocity is used. So,

Distance, [tex]d=v\times t[/tex]

v is relative velocity, v = 108 + 36 = 144 km/h

So,

[tex]d=144\ km/h \times \dfrac{1}{3}\ h\\\\d=48\ km[/tex]

So, the distance between them is 48 km after 20 minutes.

Answer:

No change

Explanation:

First, we hare to understand what we mean by buoyant force.

Archimedes Principle states that

"the buoyant force on a submerged object is equal to the weight of the fluid that is displaced by the object."

Hot air balloons rise into the air as a result of the density of the air inside the balloon is less dense i.e warmer air than the air outside the balloon i.e cooler air. This is basically how the balloons work. Now applying this to our question

Replacing Helium with less dense Hydrogen will make no difference to the buoyant force because the volume of the balloon did not change. The buoyant force depends on the weight of the displaced air, and not on the force causing the displacement.

Answer:

2.9Ω

Explanation:

Resistors are said to be in parallel when they are arranged side by side such that their corresponding ends are joined together at two common junctions. The combined resistance in such arrangement of resistors is given by;

1/Req= 1/R1 + 1/R2 + 1/R3 .........+ 1/Rn

Where;

Req refers to the equivalent resistance and R1, R2, R3 .......Rn refers to resistance of individual resistors connected in parallel.

Note that;

R1= 6.0Ω

R2 = 9.0Ω

R3= 15.0 Ω

Therefore;

1/Req = 1/6 + 1/9 + 1/15

1/Req= 0.167 + 0.11 + 0.067

1/Req= 0.344

Req= (0.344)^-1

Req= 2.9Ω

The equivalent resistance of this combination of resistors is 2.9Ω.

The combined resistance in such arrangement of resistors is provided by;

1/Req= 1/R1 + 1/R2 + 1/R3 .........+ 1/Rn

here.

Req means  the equivalent resistance and R1, R2, R3

.Rn means the resistance of individual resistors interlinked in parallel.

Also,

R1= 6.0Ω

R2 = 9.0Ω

R3= 15.0 Ω

So,

1/Req = 1/6 + 1/9 + 1/15

1/Req= 0.167 + 0.11 + 0.067

1/Req= 0.344

Req= (0.344)^-1

Req= 2.9Ω

learn more about resistance here: https://brainly.com/question/15047345

Answer:

a) 320N (if you take gravity as 10ms^-2) or 313.6N (if you take gravity as 9.8ms^-2

b) 41.6N

c) 6.25ms^-2

d) 1707.317 kg

Explanation:

a) W=mg

    W= 32 x 10 or 9.8

    W = 320N or 313.6N

b) F=ma

   F= 32 x 1.3

   F= 41.6N

c) F=ma

   200 = 32 x a

   a= 6.25ms^-2

d) F=ma

    7000= m x 4.1

     m= 1707.317 kg

I am not completely sure about the d) part because I dont whether you will be taking Friction and Normal Reaction too. As per my knowledge, I think no, as no angles nor the gradient of the floor/road is mentioned here.                  

a) The weight of your shopping cart is 313.6N .

b) The required force is  41.6N

c) The acceleration of the car is 6.25ms^-2

d) The mass of the car is 1707.317 kg.

Acceleration is rate of change of velocity with time. Due to having both direction and magnitude, it is a vector quantity. Si unit of acceleration is meter/second² (m/s²).

a) The weight of the shopping cart:  W=mg

  W= 32 x  9.8 N

 W = 313.6N

b) The required force is to be applied: F=ma

F= 32 x 1.3 N.

F= 41.6N.

c) Let the acceleration of the cart is a.

Then, force:  F=ma

200 = 32 x a

a= 6.25ms^-2

Hence,  the acceleration of the cart is  6.25ms^-2.

d) Let the mass of the car is m.

Force applied on the car: F=ma

7000= m x 4.1

m= 1707.317 kg

The mass of the car is 1707.317 kg.

Learn more about acceleration here:

brainly.com/question/12550364

#SPJ2

Answer:

fem = 0

Explanation:

The electromotive force is given by Faraday's law

         fem = - d [tex]\phi _{B}[/tex] / dt

where \phi _{B} is the flux of the magnetic field

The low magnetic flux is

         \phi _{B} = B. A = B A cos θ

substituting

      fem - d (B A cos θ) / dt

therefore for an electromotive force to exist there must be a change with respect to the time of

* The magnetic field

* The area waxed by the loop

* the angle between the magnetic field and the normal loop

* Any combination of the above

In this case, as the generator is stopped (inactive), there is no change in the parameters, therefore the electromotive force is zero (fem = 0).

Answer:

The voltage induced in the coil  is 1.25 V.

Explanation:

Given;

number of turns, N = 100 turns

cross sectional area of the copper coil, A = 0.1 m²

initial magnetic field, B₁ = 0.5 T

final magnetic field, B₂ = 1.00 T

duration of change in magnetic field, dt = 4 s

The induced emf in the coil is calculated as;

[tex]emf = -N\frac{\delta \phi}{\delta t} \\\\emf = - N (\frac{\delta B}{\delta t}) A\\\\emf = -N (\frac{B_1 -B_2}{\delta t} )A\\\\emf = N(\frac{B_2-B_1}{\delta t} )A\\\\emf = 100(\frac{1-0.5}{4} )0.1\\\\emf = 1.25 \ Volts[/tex]

Therefore, the voltage induced in the coil  is 1.25 V.

Answer:

v₂ = 306.12 m/s

Explanation:

We know that the volume flow rate of the water or any in-compressible liquid remains constant throughout motion. Therefore, from continuity equation, we know that:

A₁v₁ = A₂v₂

where,

A₁ = Area of entrance pipe = πd₁²/4 = π(0.016 m)²/4 = 0.0002 m²

v₁ = entrance velocity = 3 m/s

A₂ = Area of nozzle = πd₂²/4 = π(0.005 m)²/4 = 0.0000196 m²

v₂ = exit velocity = ?

Therefore,

(0.0002 m²)(3 m/s) = (0.0000196 m²)v₂

v₂ = (0.006 m³/s)/(0.0000196 m²)

v₂ = 306.12 m/s

Answer:

7.2 kilowatts

Explanation:

Energy= power x time

where:

power = 1,200watts to kilowatts is 1.2kw

time = 6hours

therefore,

energy = 1.2kw x 6hrs

=7.2 kilowatts

Answer:

a) d = 7.62 10⁻⁶ m, b)    l = 3.25 10⁴ m

Explanation:

Resistance is expressed by the formula

     R = ρ l / A                       (1)

density is defined by

     density = m / V

the volume of a wire is the cross section by the length

     V = A l

we substitute

     density = m / A l

     A = m / density l

we substitute in 1

     R = ρ l density l / m

     R =ρ density l² / m

     l = √ (R m /ρ density)

let's calculate the cable length

     l = √(11.7  13.5 10⁻³ / (1.68 10⁻⁸ 8.9 10³))

     l = √(10.56 10⁸)

     l = 3.25 10⁴ m

now we can find the cable diameter with the density equation

      A = m / density l

      A = 13.5 10⁻³ / (8.9 10³ 3.25 10⁴)

      A = 4,557 10⁻¹¹ m²

the area of ​​the circle is

      A = π r² = π d² / 4

      d = √ (4A /π)

      d = √ (4 4,557 10⁻¹¹/π)

      d = 7.62 10⁻⁶ m

The diameter of the wire is 0.202m and the length of the wire is 4.47*10^-5m

Data;

The resistivity of copper is calculated by

[tex]R = \frac{\rho L}{A}\\[/tex]

Let's calculated the volume of the wire first;

[tex]\rho = \frac{mass}{volume} \\volume = \frac{mass}{density} \\volume = \frac{13.5*10^-^3}{8.9*10^3} \\v = 1.52*10^-6m^3[/tex]

The diameter of the wire will be

[tex]R = \frac{\rho L}{A}\\ R = \frac{\rho LA}{A^2}\\ R = \frac{\rho V}{A^2} \\A^2 = \frac{\rho V}{R}\\ A^2 = \frac{8.9*10^3 * 1.516*10^-^6}{11.7} \\A^2 = 0.0011\\A = \sqrt{0.0011} \\A = 0.034m^2[/tex]

Taking the area

[tex]a = \pi r^2\\0.034 = 3.14 * r^2\\r^2 = \frac{0.034}{3.14} \\r^2 = 0.01083\\r = \sqrt{0.01083}\\ r = 0.104m\\d = 2r\\d = 2 * 0.104\\d = 0.208m[/tex]

Length of the wire can be calculated as

[tex]V = AL\\L = V/A\\L = \frac{1.52*10^-^6}{0.034}\\ L = 4.47*10^-^5m[/tex]

The diameter of the wire is 0.202m and the length of the wire is 4.47*10^-5m

Learn more on resistivity of a wire;

https://brainly.com/question/5595373

Answer: D) 1 and 2 tie, then 3, then 4.

Explanation: Gravitational Force is one of the 4 fundamental forces of nature (the others being eletromagnetic, weak force and strong force) and is explained by Newton's Law of Universal Gravitation, in which, every massive particle attracts every other massive particle.

The way to calculate gravitational force is:

[tex]F_{G} = \frac{GMm}{r^{2}}[/tex]

G is Universal Gravitational Constant and it is constant anywhere in the universe.

M and m are mass of each object;

r is distance between the objects;

The formula shows that gravitational force acts at an inverse square law, i.e., if objects are 2 distances apart, Force between them will decrease to one quarter of it was.

So, analysing the question, a particle inside an uniform spherical shell not at the center and at the center will have equal forces.

Outside at a distance 2r, force will be less than at a distance r.

Then the order is 1=2 > 3 > 4

Answer: [tex]4.29\times10^{14}\text{ Hz}[/tex]

Explanation:

Given: Speed of red light = 700 nm

= [tex]700\times10^{-9}[/tex] m

[tex]= 7\times10^{-7}[/tex] m

Frequency of red light = [tex]\dfrac{\text{Speed of light}}{\text{Speed of red light}}[/tex]

Speed of light = [tex]3\times10^8[/tex] m

Then, Frequency of red light = [tex]\dfrac{3\times10^8}{7\times10^{-7}}[/tex]

[tex]=0.429\times10^{8-(-7)}=0.429\times10^{15}\\\\=4.29\times10^{14}\ Hz[/tex]

Hence, Frequency of red light = [tex]4.29\times10^{14}\text{ Hz}[/tex]

The frequency of the light be in the material is [tex]4.29\times10^{14}\text{ Hz}[/tex].

Explanation:

work = force x Distance

w = 10 x 1.5 = 15Nm

The amount of work done by Kyla in lifting the bag is 15 J.

Work done on an object is defined as the cross product of the force applied on the object and the vertical displacement of the object.

Here,

Force applied by Kyla to pick up the bag, F = 10 N

Vertical displacement of the bag, s = 1.5 m

The work done by Kyla in lifting the bag,

W = F x s

W = 10 x 1.5

W = 15 J

Hence,

The amount of work done by Kyla in lifting the bag is 15 J.

To learn more about work done, click:

https://brainly.com/question/29989410

#SPJ3

Answer:

The ball traveled 0.827 m

Explanation:

Given;

distance between the metal plates of the room, d = 3.1 m

mass of the glass, m = 1.1g

charge on the glass, q = 4.7 nC

speed of the glass ball, v = 4.8 m/s

voltage of the ceiling, V = +3.0 x 10⁶ V

The repulsive force experienced by the ball when shot to the ceiling with positive voltage, can be calculated using Coulomb's law;

F = qV/d

|F| = (4.7 x 10⁻⁹ x 3 x  10⁶) / (3.1)

|F| = 4.548 x 10⁻³ N

F = - 4.548 x 10⁻³ N

The net horizontal force experienced by this ball is;

[tex]F_{net} = F_c - mg\\\\F_{net} = -4.548 *10^{-3} - (1.1*10^{-3} * 9.8)\\\\F_{net} = -15.328*10^{-3} \ N[/tex]

The work done between the ends of the plate is equal to product of the  magnitude of net force on the ball and the distance traveled by the ball.

[tex]W = F_{net} *h\\\\W = 15.328 *10^{-3} * h[/tex]

W = K.E

[tex]15.328*10^{-3} *h = \frac{1}{2}mv^2\\\\ 15.328*10^{-3} *h = \frac{1}{2}(1.1*10^{-3})(4.8)^2\\\\ 15.328*10^{-3} *h =0.0127\\\\h = \frac{0.0127}{15.328*10^{-3}}\\\\ h = 0.827 \ m[/tex]

Therefore, the ball traveled 0.827 m

The height at which the ball goes for the given parameters is; 0.827 m

We are given;

distance between the metal plates; d = 3.1 m

mass of glass; m = 1.1g = 0.0011 kg

charge on the glass; q = 4.7 nC = 4.7 × 10⁻⁹ C

speed of the glass ball; v = 4.8 m/s

voltage of the ceiling; V = +3.0 × 10⁶ V

The repulsive force experienced by the ball is gotten from the formula;

F = qV/d

|F| = (4.7 × 10⁻⁹ × 3 ×  10⁶)/3.1

|F| = 4.548 × 10⁻³ N

F = -4.548 × 10⁻³ N (negative because it is repulsive force)

The net horizontal force experienced by the ball is;

F_net = F - mg

F_net = (-4.548 × 10⁻³) - (0.0011 × 9.8)

F_net = -15.328 × 10⁻³ N

To get the height of the ball, we will use the formula;

F_net * h = ¹/₂mv²

h = (¹/₂ * 0.0011 * 4.8²)/(15.328 × 10⁻³)

We took the absolute value of F_net, hence it is not negative

h = 0.827 m

Read more about height of ball at; https://brainly.com/question/12446886

Answer:

480 Ohms

Explanation:

Resistance: This can be defined as a opposition to current flow in an electric circuit. The S.I unit of resistance is  ohms(Ω).

From the question,

V = IR................... Equation 1

Make R the subject of the equation

R = V/I............... Equation 2

V = The House voltage, I = Current, R = Resistance of the bulb.

Given: V = 240 Volts, I = 0.5 Amps.

Substitute into equation 2

R = 240/0.5

R = 480 Ohms

Hence the resistance of the bulb is 480 Ohms

Answer:

R₈₀ = 146.43 Ω

Explanation:

The resistance of a resistor depends upon many factors. One of the main factors of the change in resistance of a resistor is the change in temperature. The formula for the resistance at a temperature other than 20°C is given as follows:

R₈₀ = R₀(1 + αΔT)

where,

R₈₀ = Resistance of wire at 80°C = ?

R₀ = Resistance of wire at 20° C = 104 Ω

α = Temperature coefficient of resistance for copper = 0.0068 °C⁻¹

ΔT = T₂ - T₁ = 80°C - 20°C = 60°C

Therefore,

R₈₀ = (104 Ω)[1 + (0.0068°C⁻¹)(60°C)]

R₈₀ = 146.43 Ω

Answer:

the planet Earth is a good example

Answer:

To calculate the correct value of m if the thickness t is grown 3 times again we can deduce that:

2*(3u)*t = m* lambda

Making m the subject of the formula will give the formula:

m= 6*u*t/ Lambda

Given: Lambda= 633*10^9 while u and t are unknown

Therefore the value of m can be calculated given the formula below:

m= 6*u*t/ 633*10^9

Explanation:

To calculate the correct value of m if the thickness t is grown 3 times again we can deduce that:

2*(3u)*t = m* lambda

Making m the subject of the formula will give the formula:

m= 6*u*t/ Lambda

Given: Lambda= 633*10^9 while u and t are unknown

Therefore the value of m can be calculated given the formula below:

m= 6*u*t/ 633*10^9

Answer:

 F = 2,8289 i ^ + 1,0909 j ^) 10⁻² N

F = 3.0226 10⁻² N ,  θ  = 21.16º

Explanation:

For this exercise we use Coulomb's law

         F = k q₁q₂ / r₁₂²

We also use that the force is a vector magnitude, so we must calculate each component of the force , see the adjoint for the direction of the vectors

X axis

          Fₓ = -F₁₄ + F₁₃ₓ

Y axis

        [tex]F_{y}[/tex] = F₁₂ -F_{13y}

let's look for the expression for each force

where the side of the square is a = 1.25 m

  F₁₂ = k Q₁Q₂ / a²

  F₁₄ = k Q₁Q₄ / a²

the distance between 1 and 3 is

         d = √(a² + a²) = a √2

   F₁₃ = k Q₁Q₃ / d²

let's use trigonometry to find the components

              cos 45 = F₁₃ₓ / F₁₃

              F₁₃ₓ = F₁₃ cos 45

              F₁₃ₓ = k Q₁Q₃ / 2a²

              sin 45 = F_{13y} / F₁₃

              F_{13y} = F₁₃ sin 45

              F_{13y} = k Q₁Q₃ / 2a²  sin 45

Taking all terms, we substitute in the force for each axis

X axis

          Fₓ = - k Q₁Q₄ / a² + k Q₁Q₃ / 2a₂ cos 45

          Fₓ = k Q₁ / a² ( -Q₄ + Q₃ /2   cos 45)

          Fₓ = 9 10⁹ 1.5 10⁻⁶ / 1.25²   (- 4.5 10⁻⁶ + 3.5/2  cos 45  10⁻⁶)

          Fₓ = 8.64 10³ (3.2626 10⁻⁶)

          Fₓ = 2.8189 10⁻² N

Y axis

          F_{y} = k Q₁Q₂ / a² - k Q₁Q₃ /2a²   sin 45

          F_{y} = k Q₁ / a² (Q₂ - Q₃ /2 sin45)      

          F_{y} = 9 10⁹ 1.5 10⁻⁶/ 1.25²    (2.5 10⁻⁶ - 3.5/2   sin 45  10⁻⁶)

          F_{y} = 8.64 10³ (1.26256 10⁻⁶)

          F_{y} = 1.0909 10⁻² N

The result can be given in two ways

1) F = Fₓ i ^ + F_{y} j ^

     F = 2,8289 i ^ + 1,0909 j ^) 10⁻² N

2) in the form of a module and an angle, for which we use the Pythagorean theorem and trigonometry

       F = √ (Fₓ² + F_{y}²)

       F = 10⁻² √ (2,8189² + 1,0909²)

       F = 3.0226 10⁻² N

       tan θ = F_{y} / Fx

       θ = tan⁻¹ (F_{y} / Fₓ)

       θ = tan⁻¹ (1.0909 / 2.8189)

        θ  = 21.16º

Answer:

  x = -3 cm

Explanation:

The electrical potential is the sum of the potentials of each charge

       V = k ∑ [tex]q_{i} / r_{i}[/tex]

let's apply this to our case where the potential is V = 0 for x = 0

         0 = k (q₁ / (x₁-0) + q₂ / (x₂-0) + q₃ / (x₃-0))

in our case

q₁ = + 2.0 10⁻⁶ C

q₂ = - 6.0 10⁻⁶ C

q₃ = + 3.0 10⁻⁶ C

x₁ = -1.0 cm = 1.0 10⁻² m

x₂ = +2.0 cm = 2.0 10⁻² m

we substitute in the equation

          0 = k (2 10⁻⁶ / 1 10⁻² - 6 10⁻⁶ / 2 10⁻² + ​​3 10⁻⁶ / x)

          3 10⁻⁶ / x = 2 10⁻⁴ - 3 10⁻⁴

          3 10⁻⁶ / x = -1 10⁻⁴

           x = - 3 10⁻² m

           x = -3 cm

Answer:

Explanation:

Frequency, in physics, the number of waves that pass a fixed point in unit time; also, the number of cycles or vibrations undergone during one unit of time by a body in periodic motion. ... See also angular velocity; simple harmonic motion.

Answer:

A.) 909 cm/s

B.) 33075 N

Explanation:

A.) Given that the

Mass M = 43 g

Height h = 4.05 R

Radius r = R

At the top of the loop, the maximum potential energy P.E = mgh

Substitutes m and h into the formula where g = 9.8 m/s^2 = 9610.517 cm/s^2

P.E = 43 × 9610.517 × 4.05R

P.E = 1673671.536R J

According to conservative of energy

The maximum P.E = maximum K.E

But K.E = 1/2mv^2

1673671.536R = 1/2mv^2

Substitutes for mass m into the formula

1673671.536R = 1/2× 4.05R × v^2

The R will cancel out

Cross multiply

4.05 v^2 = 3347343.072

V^2 = 3347343.072 / 4.05

V^2 = 826504.4622

V = sqrt( 826504.4622)

V = 909 cm/s

B.) At the top of the loop, the centripetal force = the sum of the normal force N and the weight W of the car. That is,

MV^2/R = N + W

Make N the subject of formula

N = mv^2/ R - W

Where W = mg

Substitute all the parameters into the formula

N = (4.05R × 909^2) /R - 4.05R × 9610.517

N = 3346438.05 - 38922.59

N = 3307515 N

Answer:

(a) f

(b) r

(c) s

Explanation:

There are two forces on the sphere: weight and buoyancy.

Sum of forces in the y direction:

∑F = ma

B − mg = 0

B = mg

Buoyancy is equal to the weight of the displaced fluid, or ρVg, where ρ is the density of the fluid and V is the displaced volume.

ρVg = mg

ρV = m

V = m/ρ

(a) The mass decreases, so the displaced volume decreases.

(b) The sphere's density is constant and its radius increases, which means its mass increases, so the displaced volume increases.

(c) The mass stays the same, so the displaced volume is the same.

Answer:

B. The buoyant force on the copper block is greater than the buoyant force on the lead block.

Explanation:

Given;

mass of lead block, m₁ = 200 g = 0.2 kg

mass of copper block, m₂ = 200 g = 0.2 kg

density of water, ρ = 1 g/cm³

density of lead block, ρ₁ = 11.34 g/cm³

density of copper block, ρ₂ = 8.96 g/cm³

The buoyant force on each block is calculated as;

[tex]F_B = mg(\frac{density \ of \ fluid}{density \ of \ object} )[/tex]

The buoyant force of lead block;

[tex]F_{lead} = 0.2*9.8(\frac{1}{11.34} )\\\\F_{lead} = 0.173 \ N[/tex]

The buoyant force of copper block

[tex]F_{copper} = 0.2*9.8(\frac{1}{8.96})\\\\F_{copper} = 0.219 \ N[/tex]

Therefore, the buoyant force on the copper block is greater than the buoyant force on the lead block

Answer:

The factors include age and puberty

Explanation:

Glandular secretion release chemicals such as hormones in response to the body’s metabolic needs.

As an individual ages , the metabolic rate of the body also reduces . This is due to the stress and ageing of the cells of the body. This explains why glandular secretion is optimal with young people and Lower in older people. It also explains why the immune system of a young person is mostly stronger than older people.

Puberty is another factor which affects glandular secretion as during puberty there is usually a high amount of hormonal changes due to high levels of secretions of some hormones. These hormones could however inhibit the other glandular secretions.

Answer:

A& D

Explanation:

See attached file

Answer:

 v ’= 21.44 m / s

Explanation:

This is a doppler effect exercise that changes the frequency of the sound due to the relative movement of the source and the observer, the expression that describes the phenomenon for body approaching s

           f ’= f (v + v₀) / (v-[tex]v_{s}[/tex])

where it goes is the speed of sound 343 m / s, v_{s} the speed of the source v or the speed of the observer

in this exercise both the source and the observer are moving, we will assume that both have the same speed,

                v₀ = v_{s} = v ’

we substitute

               f ’= f (v + v’) / (v - v ’)

               f ’/ f (v-v’) = v + v ’

               v (f ’/ f -1) = v’ (1 + f ’/ f)

               v ’= (f’ / f-1) / (1 + f ’/ f) v

               v ’= (f’-f) / (f + f’) v

let's calculate

                v ’= (3400 -3000) / (3000 +3400) 343

                v ’= 400/6400 343

                v ’= 21.44 m / s