What do we call air in the motion​

Answer:

the sound intensity at the position of the microphone is 7.4 × 10⁻⁴ W/m²

Explanation:

Given the data in the question;

Sound power P = 26.0 W

Area of microphone A = 1.00 cm²

Radius r = 53.0 m

sound intensity at the position of the microphone = ?

Now, intensity at the position of the microphone can be determined using the following expression;

[tex]I[/tex] = P / 4πr²

We substitute

[tex]I[/tex] = 26.0 / ( 4 × π × (53.0 )² )

[tex]I[/tex] = 26.0 / ( 4 × π × 2809 )

[tex]I[/tex] = 26.0 / 35298.935

[tex]I[/tex] = 26.0 / ( 4 × π × (53.0 )² )

[tex]I[/tex] = 0.000736566

[tex]I[/tex] = 7.4 × 10⁻⁴ W/m²

Therefore, the sound intensity at the position of the microphone is 7.4 × 10⁻⁴ W/m²

Question: Find acceleration of a refrigerator 30s after a person begins pushing it at a force of 400 N, If the mass of the refrigerator is 10 kg.

Answer:

40 m/s²

Explanation:

Applying,

F = ma................Equation 1

Where F = Force applied to the refrigerator, m = mass of the refrigerator, a = acceleration of the refrigerator.

make a the subject of the equation

a = F/m............ Equation 2

From the question,

Given: F = 400 N, m = 10 kg

Substitute these values into equation 2

a = 400/10

a = 40 m/s²

Answer:

0 J

Explanation:

Since work done W = PΔV where P = pressure and ΔV = change in volume.

Since the volume is constant, ΔV = 0

So, Work done, W = PΔV = P × 0 = 0 J

So, the work done is 0 J.

Answer:

The correct answer is "8 V".

Explanation:

Given:

Potential difference across battery,

= 20 V

Potential difference across R1,

= 12 V

Now,

On applying the Kirchorff loop, we get

⇒ [tex]E-I_1R_1-I_2R_2=0[/tex]

⇒ [tex]E-V_1-V_2=0[/tex]

⇒ [tex]V_2=E-V_1[/tex]

On putting values, we get

⇒      [tex]=20-12[/tex]

⇒      [tex]= 8 \ V[/tex]  

The potential difference across the resistance R2 will be "8 Volts.

According to the kirchoff's law in a loop of a circuit when there are number of the resistances so the sum of all the potential differences will be zero.

It is given that:

Potential difference across battery,= 20 V

Potential difference across R1,= 12 V

Now,

On applying the Kirchorff loop, we get

⇒ [tex]\rm E-I_1R_1-I_2R_2=0[/tex]

⇒ [tex]\rm E-V_1-V_2=0[/tex]

⇒ [tex]\rm V_2=E-V_1[/tex]

On putting values, we get

⇒ [tex]V_2=20-12=8\ volt[/tex]

Hence the potential difference across the resistance R2 will be "8 Volts.      

To know more about Kirchoff's law follow

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Answer:

Uniform Circular Motion is the Movement or Rotation of an Object along a circular Path at constant speed.

OPTION C IS YOUR ANSWER!.

Solution :

We know, resistance is given by :

[tex]R = \dfrac{\rho l}{A}[/tex]

[tex]A = \dfrac{\rho l }{R}\\\\A = \dfrac{1.72\times 10^{-8} \times 3.5 }{0.125}\\\\A = 4.816 \times 10^{-7} \ m^2[/tex]

Now, we know mass of wire is given by :

[tex]Mass = Density \times Volume\\\\\M = 8.9 \times 10^3 \times 4.816 \times 10^{-7} \times 3.5 kg\\\\M = 0.01500\ kg\\\\M = 15.00\ gram[/tex]

Hence, this is the required solution.

Given:

The resistance will be:

→ [tex]R = \frac{\rho l}{A}[/tex]

or,

→ [tex]A = \frac{\rho l}{R}[/tex]

By substituting the values, we get

      [tex]= \frac{1.72\times 10^{-8}\times 3.5}{0.125}[/tex]

      [tex]= 4.816\times 10^{-7} \ m^2[/tex]

hence,

The mass will be:

→ [tex]Mass = Density\times Volume[/tex]

             [tex]= 8.9\times 10^3\times 4.816\times 10^{-7}\times 3.5[/tex]

             [tex]= 0.01500 \ kg[/tex]

             [tex]= 15.00 \ g[/tex]

Thus the above answer is right.  

Learn more about mass here:

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Answer:

Appliance A and B can work together without tripping

Explanation:

We will calculate the amount of current consumed by each appliances.

Appliance A

P = VI

I = P/V  

I = 250/120 = 2.08 A

Appliance B

I = 480 /120 = 4 A

Appliance C

I = 1450/120

I = 12.08 A

Hence, appliance C will trip the circuit as it consumes a lot of electricity.

Explanation:

The range R of a projectile is given by

[tex]R = \frac{v_0^2}{g} \sin 2\theta[/tex]

The maximum range [tex]R_{max}[/tex] occurs when [tex]\sin 2\theta = 1\:\text{or}\:\theta = 45°[/tex]. Let [tex]\alpha[/tex] be the angle above or below 45°. Now let's look at the ranges brought about by these angle differences.

Case 1: Angle above 45°

We can write the range as

[tex]R_+ = \dfrac{v_0^2}{g} \sin 2(45° + \alpha)= \dfrac{v_0^2}{g} \sin (90° + 2\alpha)[/tex]

[tex]\:\:\:\:\:\:\:= \dfrac{v_0^2}{g} (\sin 90° \cos 2\alpha + \cos 90° \sin 2\alpha)[/tex]

[tex]\:\:\:\:\:\:\:= \dfrac{v_0^2}{g} \cos 2\alpha\:\:\:\:\:(1)[/tex]

Case 2: Angle below 45°

We can write the range as

[tex]R_- = \dfrac{v_0^2}{g} \sin 2(45° - \alpha)= \dfrac{v_0^2}{g} \sin (90° - 2\alpha)[/tex]

[tex]\:\:\:\:\:\:\:= \dfrac{v_0^2}{g} (\sin 90° \cos 2\alpha - \cos 90° \sin 2\alpha)[/tex]

[tex]\:\:\:\:\:\:\:= \dfrac{v_0^2}{g} \cos 2\alpha\:\:\:\:\:(2)[/tex]

Note that the equations (1) and (2) are identical. Therefore, the ranges are equal if they differ from 45° by the same amount.

Answer:

the maximum vertical height the person in the cart can reach is 18.42 m

Explanation:

Given;

mass of the person, m₁ = 45 kg

mass of the cart, m₂ = 43 kg

velocity of the system, v = 19 m/s

let the maximum vertical height reached = h

Apply the principle of conservation mechanical energy;

[tex]P.E = K.E\\\\mgh_{max} = \frac{1}{2} mv^2_{max}\\\\gh_{max} = \frac{1}{2} v^2_{max}\\\\h_{max} = \frac{v_{max}^2}{2g} \\\\h_{max} = \frac{19^2}{2\times 9.8} \\\\h_{max} = 18.42 \ m[/tex]

Therefore, the maximum vertical height the person in the cart can reach is 18.42 m

Answer: The speed of gymnast at the bottom of the swing is 6.44 m/s.

Explanation:

Given: Distance = 1.06 m

According to the law of conservation of energy, the speed is calculated as follows.

[tex]mgh = - mgh + \frac{1}{2}mv^{2}\\gh = - gh + \frac{1}{2}v^{2}\\v = \sqrt{4gh}[/tex]

where,

g = acceleration due to gravity = 9.8 [tex]m/s^{2}[/tex]

h = distance

v = speed

Substitute the values into above formula as follows.

[tex]v = \sqrt{4gh}\\= \sqrt{4 \times 9.8 m/s^{2} \times 1.06}\\= 6.44 m/s[/tex]

Thus, we can conclude that speed of gymnast at the bottom of the swing is 6.44 m/s.

Answer:

plz mark brainliest again lol :)

Explanation:

When you drop a ball from a greater height, it has more kinetic energy just before it hits the floor and stores more energy during the bounce—it dents farther as it comes to a stop.

Answer:

When you drop a ball from a greater height, there is more potential energy. When you release the ball, the potential energy turns into kinetic energy. When the ball bounces off the ground, the ball go upward and then it has more potential energy. Then when it goes down it has more kinetic energy. The ball keeps doing this until there is not enough potential energy left.

Explanation:

Answer:

378 KWh

Explanation:

We'll begin by converting 1.2×10³ W to KW. This can be obtained as follow:

10³ W = 1 KW

Therefore,

1.2×10³ W = 1.2×10³ W × 1 KW / 10³ W

1.2×10³ W = 1.2 KW

Next, we shall convert 6.3×10² mins to hours (h). This can be obtained as follow:

60 mins = 1 h

Therefore,

6.3×10² mins = 6.3×10² mins × 1 h / 60 mins

6.3×10² mins = 10.5 h

Finally, we shall determine the electrical energy in KWh used for 1 month (i.e 30 days). This can be obtained as follow:

Power (P) = 1.2 KW

Time (t) for 1 month (30 days) = 10.5 h × 30

= 315 h

Energy (E) =?

E = Pt

E = 1.2 × 315

E = 378 KWh

Thus, the electrical energy used for 1 month (i.e 30 days) is 378 KWh.

Answer:

2.0km/h.

Explanation:

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This question is incomplete, the complete question is;

Model a hydrogen atom as a three-dimensional potential well with U₀ = 0 in the region 0 < x < L, 0 < y < L and 0 < z < L, and infinite otherwise, with L = 1.0 × 10⁻¹⁰ m.

Which of the following is NOT one of the lowest three energy levels of an electron in this model?

a. 283 eV

b. 339 eV

c. 113   eV  

d. 226 eV        

Answer:

the lowest three energy are; 113 eV, 225 eV, and 339 eV.

Hence Option a) 283 eV is not among the three lowest energy

Explanation:

Given the data in the question;

Three dimension cube or particle in a cubic box

the energy value is given by;

[tex]E_{nx,ny,nz[/tex] = [tex]( n_x^2 + n_y^2 + n_z^2 )[/tex] × π²h"² / 2ml²

where h" = h/2π and h is Planck's constant ( 6.626 × 10⁻³⁴ m² kg / s )

m is mass of electron ( 9.1 × 10⁻³¹ kg )

l is length of side of box ( 1.0 × 10⁻¹⁰ m )

for ground level ( [tex]n_x = n_y = n_z = 1[/tex] )

so

[tex]( n_x^2 + n_y^2 + n_z^2 )[/tex] ×  π²h"² / 2ml²

since h" = h/2π

[tex]( n_x^2 + n_y^2 + n_z^2 )[/tex] × π²h² / (2π)²2ml²

so we substitute

[tex]E_{111[/tex] = ( 1² + 1² + 1² ) × [ π²( 6.626 × 10⁻³⁴ )² ] / [ (2π)² × 2 × 9.1 × 10⁻³¹ kg × ( 1.0 × 10⁻¹⁰)² ]

[tex]E_{111[/tex] = 3 × [ (4.333188779 × 10⁻⁶⁶) / ( 7.185072 × 10⁻⁴⁹ ) ]    

[tex]E_{111[/tex] = 3 × [ 6.03082165 × 10⁻¹⁸ ]

Now, we know that electric charge = 1.602 x 10⁻¹⁹

so

[tex]E_{111[/tex] = 3 × [ (6.03082165 × 10⁻¹⁸) / (1.602 x 10⁻¹⁹) ]

[tex]E_{111[/tex] = 3 × [ 37.645578 ]

[tex]E_{111[/tex] = 112.9 ≈ 113 eV

[tex]E_{211[/tex] = [tex]( n_x^2 + n_y^2 + n_z^2 )[/tex]  × π²h² / (2π)²2ml²

we substitute

[tex]E_{211[/tex] = ( 1² + 1² + 2² ) × [ 37.645578 ]

[tex]E_{211[/tex] = 6 × [ 37.645578 ]

[tex]E_{211[/tex] = 225.87 ≈ 226 eV

[tex]E_{221[/tex] = [tex]( n_x^2 + n_y^2 + n_z^2 )[/tex]  × π²h² / (2π)²2ml²

we substitute

[tex]E_{221[/tex] = ( 2² + 2² + 1² ) × [ 37.645578 ]

[tex]E_{211[/tex] = 9 × [ 37.645578 ]

[tex]E_{211[/tex] = 338.8 ≈ 339 eV

Therefore, the lowest three energy are; 113 eV, 225 eV, and 339 eV.

Hence Option a) 283 eV is not among the three lowest energy

Answer: Pressure increases as the depth increases.

Answer:

depths cause it help it with a lot and that it the answer

Answer:

v_f = 10.38 m / s

Explanation:

For this exercise we can use the relationship between work and kinetic energy

          W = ΔK

note that the two quantities are scalars

Work is defined by the relation

          W = F. Δx

the bold are vectors.  The displacement is

          Δx = r_f -r₀

          Δx = (11.6 i - 2j) - (4.4 i + 5j)

          Δx = (7.2 i - 7 j) m

          W = (4 i - 9j). (7.2 i - 7 j)

remember that the dot product

           i.i = j.j = 1

           i.j = 0

           W = 4  7.2 + 9  7

           W = 91.8 J

the initial kinetic energy is

           Ko = ½ m vo²

           Ko = ½ 2.0 4.0²

           Ko = 16 J

we substitute in the initial equation

          W = K_f - K₀

          K_f = W + K₀

          ½ m v_f² = W + K₀

          v_f² = 2 / m (W + K₀)

          v_f² = 2/2 (91.8 + 16)

           v_f = √107.8

          v_f = 10.38 m / s

Answer:

According to the parallelogram law of vector addition if two vectors act along two adjacent sides of a parallelogram(having magnitude equal to the length of the sides) both pointing away from the common vertex, then the resultant is represented by the diagonal of the parallelogram passing through the same common vertex

Explanation:

DL: Activity 2.3 Resistance

Complete the questions based on the Resistance presentation.

a. All resistors ___________ or _____________ the flow of electrons.

b. As resistance __________________ current _______________________

a) limits or opposes

b) increases, decreases

Resistors are electrical devices used to resist, limit, oppose or hinder the flow of electrons in a circuit. This resistance causes a reduction in current and an increase in voltage in the circuit. In order words, as resistance increases, the current decreases and voltage increases.

This was further stated by Ohm's law that states that as long as the resistance in a wire/conductor remains constant, the voltage across it is directly proportional to the current flowing through a conductor. i.e

V = IR

Where;

R = constant called resistance

I = current flowing through the wire

V = voltage across the wire

Answer:

(a) 490 N

(b) 490 N

(c) 540 N

Explanation:

mass, m = 50 kg

acceleration, a = 1 m/s2

(a) The weight is given by

W = m g = 50 x 9.8 = 490 N

(b) The normal force is

N = m g = 490 N

(c) Let the force required is F.

Use Newton's second law

F - m g = m a

F = m(g + a)

F = 50(9.8 + 1)

F = 540 N

Answer:

Here are a few recommendations based on IOM's Migration Governance Framework: Countries should promote stability, education and employment opportunities and reduce the drivers of forced migration, including by promoting resilience, thereby enabling individuals to make the choice between staying or migrating.

Explanation:

thank me later

Answer:

Energy conversion in flashlight.

Explanation:

When the switch of a flashlight is on, then the batteries inside them will be connected in a circuit and chemical energy from the batteries will be converted into electrical energy and then the electrical energy will be converted into light energy.

Light energy is also called electromagnetic energy.

Hence, among the given options the correct one is the first option that is:

1. Electrical energy into electromagnetic energy is the answer.

Answer:

[tex]m=1.47\times 10^{-24}\ Kg[/tex]

Explanation:

Given that,

Charge, [tex]q=1.6\times 10^{-19}\ C[/tex]

Revolution = 7 rev

magnetic field, B = 45 mT

Time, t = 1.29 ms

We need to find the mass of the ion. Let m be the mass. The formula for the mass in terms of time period is given by :

[tex]m=\dfrac{qBT}{2\pi}\\\\m=\dfrac{1.6\times 10^{-19}\times 45\times 10^{-3}\times 1.29\times 10^{-3}}{2\pi}\\\\m=1.47\times 10^{-24}\ Kg[/tex]

So, the mass of the ion is equal to [tex]1.47\times 10^{-24}\ Kg[/tex].

Answer:

7.48 cm

Explanation:

The diagrammatic representation of information is shown in the image below:

From the image, Δ X₁X₂ and Δ Y₁Y₂ are equivalent triangles.

where;

X₁X₂ = width of the aperture

Using equivalent triangles, It implies that:

[tex]\implies \dfrac{X_1X_2}{Y_1Y_2} = \dfrac{1.70}{1.70+0.800} \\ \\ \implies X_1X_2=\dfrac{1.70}{1.70+0.800}\times 11.0[/tex]

[tex]X_1X_2= \dfrac{1.70}{2.50}\times 11.0 cm[/tex]

X₁X₂ = 7.48 cm

Answer:

Magnetic Field

Explanation:

The area around a magnet containing all of magnetic Lines of force is called the magnetic field.

Answer:

i = 4.9 A

Explanation:

The expression for the magnetic force in a wire carrying a current is

          F = i L x B

bold letters indicate vectors.

The direction of the cable is towards the East, the direction of the magnetic field is towards the North, so the vector product is in the vertical direction (z-axis) upwards and the weight of the cable is vertical downwards. Let's apply the equilibrium condition

            F - W = 0

            i L B = m g

They indicate the linear density of the cable λ = 0.2 kg / m

           λ = m / L

           m = λ L

we substitute

           i B = λ g

           i = [tex]\frac{ \lambda \ g}{B}[/tex]

let's calculate

          i = 0.2 9.8 / 0.4

          i = 4.9 A

Answer:

[tex]68.0^{\circ}[/tex]

Explanation:

A projectile's vertical velocity at the top of its flight path must be zero, therefore the speed at the top of the trajectory must be referring to the object's horizontal velocity. Since there are exactly zero horizontal forces acting on the object, its horizontal velocity will remain the exact same throughout the entire launch. Thus, the horizontal component of the initial launch must be  45 meters per second, and we have the following equation using basic trigonometry for a right triangle:

Let [tex]\theta[/tex] be the unknown angle above the horizontal.

[tex]\cos \theta=\frac{45}{120},\\\theta=\arccos(\frac{45}{120})=67.97568716^{\circ}\approx \boxed{68.0^{\circ}}[/tex]