why does a hot air balloon fall when the air inside is not heated​

Answer:

c) A series of RC circuits.

Answer:

[tex]118\; \rm Hz[/tex].

Explanation:

The frequency [tex]f[/tex] of a wave is equal to the number of wave cycles that go through a point on its path in unit time (where "unit time" is typically equal to one second.)

The wave in this question travels at a speed of [tex]v= 295\; \rm m\cdot s^{-1}[/tex]. In other words, the wave would have traveled [tex]295\; \rm m[/tex] in each second. Consider a point on the path of this wave. If a peak was initially at that point, in one second that peak would be

How many wave cycles can fit into that [tex]295\; \rm m[/tex]? The wavelength of this wave[tex]\lambda = 2.50\; \rm m[/tex] gives the length of one wave cycle. Therefore:

[tex]\displaystyle \frac{295\;\rm m}{2.50\; \rm m} = 118[/tex].

That is: there are [tex]118[/tex] wave cycles in [tex]295\; \rm m[/tex] of this wave.

On the other hand, Because that [tex]295\; \rm m[/tex] of this wave goes through that point in each second, that [tex]118[/tex] wave cycles will go through that point in the same amount of time. Hence, the frequency of this wave would be

Because one wave cycle per second is equivalent to one Hertz, the frequency of this wave can be written as:

[tex]f = 118\; \rm s^{-1} = 118\; \rm Hz[/tex].

The calculations above can be expressed with the formula:

[tex]\displaystyle f = \frac{v}{\lambda}[/tex],

where

Answer:

118

Explanation:

Answer:

55 MW.

Explanation:

So, we are given the following data or parameters Below;

=> "2.0 MW is to arrive at a large shopping mall over two 0.100Ω line.

=> " the voltage is stepped up from 120 V to 1200 V and then down again, rather than simply transmitting at 120 V."

=> "Assume the transformers are each 99% efficient."

STEP ONE: determine the current in the transmission line.

Output Current, i = Power/ voltage.

Output Current,i = (2.0 MW × 10^6 W/ 1 MW)/120.

Output Current,i = 1.66 × 10^4 A.

Therefore, current in the transmission line = output voltage × output current/99% × line voltage.

= 120 × 1.66 × 10^4/ 99% × 1200 = 1.68 × 10^3 A.

STEP TWO: determine the power loss in the two lines.

Power loss = i^2 × Resistance

Power loss = (1.66 × 10^4 )^2 × 0.1 × 2 = 5.5 × 10^7 watt.

STEP THREE: determine the power generated.

Power generated = 2 × 10^6 +5.5 × 10^7.

Power generated = 5.57 × 10^7 watt.

STEP FOUR: determine the step down transformer power.

= 2 × 10^6/99% = 2.02 × 10^6.

Thus, 2.02 × 10^6 + 5.57 × 10^5 = 2.58 × 10^6 watt.

STEP FIVE: Determine the total power and the saved power.

Total power = 2.58 × 10^6/ 99%= 2.6 × 10^6.

Saved power = 5.7 × 10^7 - 2.6 × 10^6 .

Conversion to MW gives saved power = 55 MW.

=

Answer:

Center of Gravity is the point in a body where the gravitational force may be taken to act.  Center of Buoyancy is the center of gravity for the volume of water which a hull displaces.

Answer:

The minimum riding speed relative to the whistle (stationary) to be able to hear the sound at 21.0 kHz frequency is 15.7  m/s

Explanation:

The Doppler shift equation is given as follows;

[tex]f' = \dfrac{v - v_o}{v + v_s} \times f[/tex]

Where:

f' = Required observed frequency = 20.0 kHz

f = Real frequency = 21.0 kHz

v = Sound wave velocity = 330 m/s

[tex]v_o[/tex] = Observer velocity = X m/s

[tex]v_s[/tex] = Source velocity = 0 m/s (Assuming the source is stationary)

Which gives;

[tex]20 = \dfrac{330- v_o}{330+0} \times 21[/tex]

330 - [tex]v_o[/tex] = (20/21)*330

[tex]v_o[/tex] = 330 - (20/21)*330 = 15.7 m/s

The minimum riding speed relative to the whistle (stationary) to be able to hear the sound at 21.0 kHz frequency = 15.7  m/s.

Answer:

v_squid = - 2,286 m / s

Explanation:

This exercise can be solved using conservation of the moment, the system is made up of the squid plus the water inside, therefore the force to expel the water is an internal force and the moment is conserved.

Initial moment. Before expelling the water

          p₀ = 0

the squid is at rest

Final moment. After expelling the water

         [tex]p_{f}[/tex] = M V_squid + m v_water

         p₀ = p_{f}

          0 = M V_squid + m v_water

           c_squid = -m v_water / M

The mass of the squid without water is

            M = 9 -2 = 7 kg

let's calculate

           v_squid = 2 8/7

           v_squid = - 2,286 m / s

The negative sign indicates that the squid is moving in the opposite direction of the water

Answer:

Electric flux;

Φ = 30.095 × 10⁴ N.m²/C

Explanation:

We are given;

Charge on plate; q = 17 µC = 17 × 10^(-6) C

Area of the plates; A_p = 180 cm² = 180 × 10^(-4) m²

Angle between the normal of the area and electric field; θ = 4°

Radius;r = 3 cm = 3 × 10^(-2) m = 0.03 m

Permittivity of free space;ε_o = 8.85 × 10^(-12) C²/N.m²

The charge density on the plate is given by the formula;

σ = q/A_p

Thus;

σ = (17 × 10^(-6))/(180 × 10^(-4))

σ = 0.944 × 10^(-3) C/m²

Also, the electric field is given by the formula;

E = σ/ε_o

E = (0.944 × 10^(-3))/(8.85 × 10^(-12))

E = 1.067 × 10^(8) N/C

Now, the formula for electric flux for uniform electric field is given as;

Φ = EAcos θ

Where A = πr² = π × 0.03² = 9π × 10^(-4) m²

Thus;

Φ = 1.067 × 10^(8) × 9π × 10^(-4) × cos 4

Φ = 30.095 × 10⁴ N.m²/C

Answer:

Explanation:

force on charge q  in electric field E = q E

force on charge of bee in given electric field

= 23 x 10⁻¹² x 100

= 23 x 10⁻¹⁰ N

weight of honey bee = .10 x 10⁻³ x 9.8

= 9.8 x 10⁻⁴ N

Ratio of force / weight of bee

= 23 x 10⁻¹⁰  / 9.8 x 10⁻⁴

= 2.347 x 10⁻⁶ .

Answer:

t=7.25 sec

Explanation:

840=16t'2,

Answer:

The safe distance is 199 cm approximately 200 cm

Explanation:

Safe intensity = 1.00 W/m^2

wattage of radar leaked radar = 50.0 W

safe distance from the microwave will be = ?

We know that the intensity of a wave radiated uniformly in all direction is given as

[tex]I[/tex] = [tex]\frac{W}{A}[/tex]

where

W is the wattage of the leaked radar

A is the radial area, which is the area of a sphere that encapsulates the region through which this wave spreads uniformly.

From the equation above,

[tex]A[/tex] = [tex]\frac{W}{I}[/tex] = 50/1 = 50 m^2

But the area of this sphere [tex]A[/tex] = [tex]4\pi r^{2}[/tex]

where

r is the safe distance from the radar source

substituting for the area, we have

50 = 4 x 3.142 x [tex]r^{2}[/tex]

50 = 12.568 [tex]r^{2}[/tex]

[tex]r^{2}[/tex] = 50/12.568 = 3.978

r = [tex]\sqrt{3.978}[/tex] = 1.99 m = 199 cm ≅ 200 cm

Answer:

The two middle chains are for suspension of the glass surface, while the fours chains at all corners prevents tilting

Explanation:

From the picture, the the frame bearing the glass surface is suspended by the two metal chains at the middle,

While the balance to avoid tilting to either directions is maintained by the four  chains at all corners.

Answer:

165.73 K

Explanation:

The computation of HooRU's temperature is shown below:-

As per the stefan's law, the power radiated by black body radiations which is

[tex]P = eA\sigma T^4[/tex]

where  

A indicates surface area

e indicates emissitivity

T indicates temperature

now, we will put the values in the above equation

[tex]13.5 = 0.209 \times 1.51 \times \sigma \times T^4[/tex]

After solving the above equation we will get temperature which results

= 165.73 K

Therefore for computing the HooRU's temperature we simply applied the above formula.

Answer:

That is true and is easily explained by the next equation:

W= m*g

where

W= Weight

m=mass

g= gravitational acceleration

so, if you use a spring balance in another planet with a different gravitational acceleration the measured weight will be different.

The correct answer is D. The movement of the molecules will gradually increase.

Explanation:

At the beginning of the model the state of matter of the water is solid, in this, particles have a defined arrangement and are together, which stops particles from moving freely and only allows them to vibrate. However, as the substance is heated the thermal energy (heat) increases in the sample, this causes particles to move more and the arrangement of it changes. Due to this, when the ice melts and there is liquid water particles move more than in solid states, which makes ice lacks a defined shape. Moreover, as the heat continues to increase the thermal and kinetic energy (movement) increases, indeed in gas state (water vapor) particles will move freely. This means the movement or kinetic energy in particles gradually increases in the model.

Answer: D

Explanation:

Answer:

The correct option is

a. The inductive reactance is doubled and the capacitive reactance is halved

Explanation:

For a series RLC circuit, is a resonant circuit such that the impedance, Z, is minimum at the resonance frequency

Also we have that the capacitive reactance [tex]X_C[/tex], is given as follows;

[tex]X_c = \dfrac{1}{\omega \cdot C}[/tex]

Where;

ω = Angular frequency = 2πf

Where;

f = The frequency in the circuit

[tex]\therefore X_c = \dfrac{1}{2 \cdot \pi \cdot f \cdot C}[/tex]

The inductive reactance is also given as follows;

[tex]X_L = \omega \cdot L = 2 \cdot \pi \cdot f \cdot L[/tex]

Therefore, when the circuit frequency doubles, the inductive reactance doubles and the capacitive reactance halves

When the alternating current frequency in a series RLC circuit is halved,  the inductive reactance is doubled and the capacitive reactance is halved.

An Alternating current (ac) frequency is known to be the amount of cycles per second that can be found  in an ac sine wave.

The Frequency is known to be the rate through which the current changes direction in terms of per second. It is said to be often measured in hertz (Hz). Note that the alternating current frequency in a series RLC circuit is halved,  the inductive reactance increases and the capacitive reactance is reduced.

Learn more about  alternating current from

https://brainly.com/question/15595203

Answer:

cluttered

Explanation:

The correct word to describe the garage would be cluttered.

A place is said to be cluttered when it is filled with an untidy collection of material things. In this case, the garage is filled with materials such as bike wrenches, tires, frames, etc.

Inviting can also mean tempting, attractive, etc, and has no relevance to the condition of the garage as described in the excerpt.

Dangerous can also mean harmful, and not the right word to describe the garage.

Sparse can also mean scanty, scattered, and would be the opposite of the condition of the garage.

Correct answer: cluttered

Answer:

c.  cluttered

Explanation:

The electric potential at the geometric center of this rectangle is determined as 43.2 V.

Potential at the center of the rectangle is calculated as follows;

Distance from each corner to the center is calculated as follows;

[tex]x = \sqrt{(a/2)^2 + (b/2)^2}[/tex]

Potential due to four point charges is calculated

[tex]V = \frac{kq}{x} \\\\V =4 (\frac{kq}{x} )\\\\V = 4(\frac{kq}{\sqrt{(a/2)^2 + (b/2)^2} } )\\\\V = \frac{4 \times 9\times 10^{9}\times 6\times 10^{-9}}{\sqrt{(6/2)^2 + (8/2)^2} } \\\\V = \frac{4 \times 9\times 10^{9}\times 6\times 10^{-9}}{5} \\\\V = 43.2 \ Volts[/tex]

Learn more about electric potential here: https://brainly.com/question/14306881

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Answer:

Destroy information about the speed of the particle

Explanation:

This is according to Heisenberg's Uncertainty Principle states that there is inherent uncertainty in the act of measuring a variable of a particle. Commonly applied to the position and momentum of a particle, the principle states that the more precisely the position is known the more uncertain the momentum is and vice versa.

Answer and Explanation:

For computing the displacement at point B and D we need to determine the following calculations

[tex]P_Net = P_C + P_E + P_B[/tex]

= 250 + 350 - 50

= 550 N

Now the deflection for bar AB is

[tex]\delta_{AB} = \frac{PL_{AB}}{AE} \\\\ = \frac{550 \times 500}{6,000 \times 200 \times 10^{3}}[/tex]

Now for bar BC it is

[tex]\delta_{BC} = \frac{PL_{BC}}{AE} \\\\ = \frac{(550 + 50) \times 250}{5,000 \times 200 \times 10^{3}} \\\\ = 1.5 \times 10^{-04} mm[/tex]

And for bar CD it is

[tex]\delta_{CD} = \frac{PL_{CD}}{AE} \\\\ = \frac{(550 -250 + 50) \times 250}{5,000 \times 200 \times 10^{3}} \\\\ = 0.875 \times 10^{-4} mm[/tex]

Now the displacement is as follows

For B

2.292 × 10^{-4} mm

For D, it is

[tex]= 2.292 \times 10^{-4} + 1.5 \times 10^{-4} + 0.875 \times 10^{-4} mm \\\\ = 4.667 \times 10^{-4} mm[/tex]

We simply applied the above formulas for determining the  displacements at points B, D and the same is to be considered  

Answer:

The correct option is;

d) Parallel to the plane

Explanation:

The forces acting on the box of mass, m are;

Weight of the box acting an angle, θ, equal to the inclination of the plane to the perpendicular of the plane

Weight of the box acting along the plane = m×g×sin(θ)

The force of friction along the plane = μ×m×g×cos(θ)

The total force acting downward along the plane [tex]F_{down}[/tex], = m×g×sin(θ) + μ×m×g×cos(θ)

The Force needed to pull the box up along the plane F = The total force acting downward along the plane

F = m×g×sin(θ) + μ×m×g×cos(θ) = m×g×(sin(θ) + μ×cos(θ))

When the force, Fₐ is applied vertically, the force acting along the plane = Fₐ×cos(θ)

When the force is applied perpendicular, the force acting along the plane = Fₐ×sin(θ)

When the force is applied horizontally, the force acting along the plane = Fₐ×cos(θ)

When the force is applied parallel to the plane, the force acting along the plane = Fₐ

Therefore, since Fₐ > Fₐ×cos(θ) and Fₐ > Fₐ×sin(θ), for acute angles, we have that the least force is required when the force is acting parallel to the plane.

Answer with explanation:

Complete question is provided in the attachment below.

There are 3 undefined term in geometry :1) A Point  2)  A line 3) A Plane.

When two lines are parallel they never meet , so the requirement to define them is lines and a plane on which they lie.

While when two lines are perpendicular , they intersect each other at a point by making a right angle between them.

So it required lines and a point to define it.

Answer:

Explanation:

Solution,

When a certain object comes in motion from rest, in the case, initial velocity = 0 m/s

Initial velocity ( u ) = 0 m/s

Final velocity ( v ) = 72 km/h ( Given)

We have to convert 72 km /h in m/s

[tex]72 \: km \: per \: hour[/tex]

[tex] = 72 \times \frac{1000}{60 \times 60} [/tex]

[tex] = 20 [/tex] m/s

Final velocity ( v ) = 20 m/s

Time taken ( t ) = 2 seconds

Acceleration (a) = ?

Now,

we have,

[tex]a = \frac{v - u}{t} [/tex]

[tex]a = \frac{20 - 0}{2} [/tex]

[tex]a = \frac{20}{2} [/tex]

[tex]a = 10 [/tex] m/s ^2

Hope this helps...

Good luck on your assignment..

Answer:

38.6 N

2.57 m/s²

Explanation:

Draw a free body diagram of the box.  There are four forces:

Weight force mg pulling down,

Normal force N pushing up,

Friction force Nμ pushing left,

and applied force P pulling at an angle 40°.

Sum of forces in the y direction:

∑F = ma

N + P sin 40° − mg = 0

N = mg − P sin 40°

The net force in the x direction is:

∑F = P cos 40° − Nμ

∑F = P cos 40° − (mg − P sin 40°) μ

∑F = P cos 40° − mgμ + Pμ sin 40°

∑F = P (cos 40° + μ sin 40°) − mgμ

Plugging in values:

∑F = (80 N) (cos 40° + 0.23 sin 40°) − (15 kg) (10 m/s²) (0.23)

∑F = 38.6 N

Net force equals mass times acceleration:

∑F = ma

38.6 N = (15 kg) a

a = 2.57 m/s²

Answer:

[tex]\sf Proof \ below[/tex]

Explanation:

We know that acceleration is change in velocity over time.

[tex]\sf a=\frac{\triangle v}{t}[/tex]

[tex]\sf a=\frac{v-u}{t}[/tex]

v is the final velocity and u is the initial velocity.

Solve for v.

Multiply both sides by t.

[tex]\sf at=v-u[/tex]

Add u to both sides.

[tex]\sf at + u=v[/tex]

Answer:

Acceleration = v-u/t  when we flip -u and t to right hand side

then -u changes to plus and denominator t changes to numerator

then then  this equations becomes  v=u+at

Explanation:

Answer:

It slows down as the cross-section becomes smaller is the correct answer to this question.

Explanation:

Answer:

1.) F = 5.3×10^-3 N

2.) Positive y - direction

Explanation:

The parameters given are:

Charge q = 0.0005C

Velocity V = 2.5010 m/s

Magnetic field B = 4.2 T

Magnetic force F = BVqsinØ

F = BVq

since Ø = 90 degree

Substitute all the parameters into the formula

F = 4.2 × 2.5010 × 0.0005

Therefore, the magnetic force on a particle is F = 5.3 × 10^-3 N

2.) According to Fleming's left hand rule, the direction of the magnetic force will be perpendicular to the magnetic field which moving upward of the screen.

Answer:

it’s f=0.0005 x 2.5 x 10^5 x 4.20

F= 525 N

+ y direction (up)

Explanation:

got it right

Answer: 2 seconds

Explanation:

Since I've only memorized a couple of formulas for these things, I need to do the time first:

I'll use the formula  Distance = (1/2) (acceleration) (time)²

20 m = (1/2) (10 m/s²) (time)²

Time² = (20 m) / (5 m/s²)

Time² = 4 sec²

Time = 2 seconds

Now ...

-- When the ball hits the ground, it has been falling for 2 seconds.

-- Its acceleration has caused its speed to increase by 10 m/s every second.

-- So after 2 seconds, its speed has grown to (2 s) (10 m/s²) = 20 m/s .

Answer:

15.96 m³ (corrected to 2 d.p.)

Explanation:

Using idea gas law:

pV = nRT

pressure p = 125000 Pa

volume V = unknown

no. of moles n= 3.27 moles

ideal gas constant R = 8.3145 J K−1 mol−1

Temperature t (in Kelvins) = 15 + 273.15 = 288.15K

125000 x v = 3.27 x 8.3145 x 288.15

v = 15.96 m³ (corrected to 2 d.p.)

Answer:

0.0626 m^3

Explanation:

First, we know that the equation to calculate the behavior of gases is:

PV=nRT

Looking at the problem, we understand that we are needing to solve for V, which means we need to isolate V to solve for it.

The new equation will look something like this:

V=nRT/P

The last step is to simply plug in the remaining variables:

n=3.27

R=8.31 (that is not given but is a standard number that you will always use for "R"/ the ideal gas constant-it helps to right it down somewhere to reference it if you ever need it!)

P=125000

T=288 (the temp needs to be in degrees K, so take 15.0 degrees c and + 273)

Finally, when you input all of those, you will have something that looks like this:

V=(3.27*8.31*288)/125000

V=0.02608205 m^3

V= 0.0626 m^3 (rounded to 3 sig. figs)

I hope this was helpful and easy to understand!

Answer:

greatest displacement = 44.1m

initial velocity= 29.4m/s

Explanation:

Greatest displacement

s=1/2at^2

= (9.8/2 ×9)m

= 44.1m

initial velocity

s=ut-1/2at^2

44.1= 3u -(1/2×9.8×9)

44.1=3u-44.1

3u=88.2

u=29.4m/s