hi! hina can you help me with those 2 questions ​

Answer:

the velocity of the acorn

Explanation:

just do in in real life and see

Answer:

it is probably the velocity of the acorn

Answer:

A) I = 0.09947 W , β = 109 db , B) β = 116 db , β = 116 db , c) Δβ = 7 dB,

D)  P = 50.27 W

Explanation:

A) The intensity of a spherical sound wave is

          I = P / A

where A is the area of ​​the sphere where the sound is distributed

          A = 4π R²

we substitute

          I = P / 4πR²

let's calculate

          I = 500 / (4π 20²)

          I = 0.09947 W

to express this quantity in decibels we use relate

         β = 10 log (I / I₀)

The detectivity threshold is I₀ = 1 10⁻¹² W / m²

         β = 10 lob (0.09947 / 10⁻¹²)

         β = 10 (10.9976)

         β = 109 db

B) intensity at r = 10m

          I = 500 / (4π 10²)

          I = 0.3979 W / m²

          β = 10 log (0.3979 / 10⁻¹²)

          β = 10 (11.5997)

          β = 116 db

C) the change in intensity in decibles is

          Δβ = β₁ - β₂

          Δβ = 116 - 109

          Δβ = 7 dB

D) let's find the intensity for 100 db

          I = I₀ 10 (β / 10)

          I = 10⁻¹² 10 (100/10)

          I = 10⁻² W / m²

Thus

           P = I A

           P = I 4π R²

           P = 10⁻² 4π 20²

           P = 50.27 W

Answer:

Explanation:

Given

Distance = 4.0m

Time = 5.0 mins = 300secs

Required

Average speed

Average speed = Distance/Time

Average speed = 4.0/300

Average speed = 0.01333m/secs

Hence the average speed of the snail is 0.01333m/s

Answer:

[tex]P=2.57\times 10^{-7}\ N/m^2[/tex]

Explanation:

Given that,

A radio wave transmits 38.5 W/m² of power per unit area.

A flat surface of area A is perpendicular to the direction of propagation of the wave.

We need to find the radiation pressure on it. It is given by the formula as follows :

[tex]P=\dfrac{2I}{c}[/tex]

Where

c is speed of light

Putting all the values, we get :

[tex]P=\dfrac{2\times 38.5}{3\times 10^8}\\\\=2.57\times 10^{-7}\ N/m^2[/tex]

So, the radiation pressure is [tex]2.57\times 10^{-7}\ N/m^2[/tex].

Answer:

Magnetic field lines can be drawn by moving a small compass from point to point around a magnet. At each point, draw a short line in the direction of the compass needle.When opposite poles of two magnets are brought together, the magnetic field lines join together and become denser between the poles.

Explanation:

0.11m/s

Explanation:

avg. velocity = total displacement/ total time

total displacement = 2.55 - 1.09

= 1.46

total time taken = 12.8s

avg velocity = 1.46/12.8

=0.11

Alpha Centauri is 4.4 lightyears away. Traveling at 1/10 speed of light it would take you 44 years.

Answer: 1.8x10 sqaured newtons for all plato users

Explanation:

The value of the normal force of reaction is 181.8 N

Friction is defined as the resistance to motion caused by the contact between a surface and the object moving against it.

The normal reaction force is the weight of the body experiencing friction and normally acts vertically downwards.

The frictional force, the coefficient of kinetic friction and the normal force are related by the formula:

coefficient of friction = frictional force / normal reaction

Therefore, normal reaction = frictional force / coefficient of friction

Frictional force = 40 N;   coefficient of kinetic friction friction is 0.22

Normal reaction = 40 N/ 0.22 = 181.8 N

Therefore, the value of the normal force of reaction is 181.8 N

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Answer:

Thymol blue

Explanation:

Answer: c

Explanation:

Answer:

Tension= 475N

Force= 225N

Explanation:

The question is not complete, here is the complete question

Also, see attached a free body diagram for your reference

"A 20.0-kg uniform plank is supported by the floor at one end by a vertical rope at the other as shown in the figure. A 50.0-kg mass person stands on the plank a distance three-fourths of the length plank from the end on the floor.

a. What is the tension in the rope?

b. What is the magnitude of the force that the floor exerts on the plank?"

given data

mass of man=50kg

mass of plank=20kg

length of plank=10m

let us make the lenght of the rope be d

The torque about the floor

That is taking moment about the floor

[tex]N*0+T*d=20*10*d/2 + 50*10*3d/4\\\\T=100+375=475N\\\\[/tex]

Force will be also zero  

[tex]N+T=20*10+50*10\\\\N+T=700 \\\\N=700-475=225 newtons\\\\N+T=20*10+50*10\\\\N+T=700\\\\N=700-475=225newtons[/tex]

Answers:

Question 1: 3 sig figs

Question 2: 4 sig figs

Question 3: 5 sig figs

Question 4: 8 sig figs

The rule for sig figs:

Any number after a zero in a decimal is one sig fig.

Example: 0.00359, it has three sig figs.

Also, remember if there are zeros after a number greater than zero, it is also a sig fig as well.

Hope this helps you!

Answer:

1) 3 sf  2) 3 sf  3) 5 sf  4) 6 sf

Explanation:

00s at the start dont count towards the sig figs and 00s at the end dont either but 00s in the middle do

your welcome :)

Answer:

Explained below

Explanation:

In skying down a hill, usually the skiers start at an elevated position and this means that they possess a large quantity of potential energy since they are in vertical position.

Now, as the skiers start to descend down the hill, they will lose potential energy while they gain kinetic energy since they are in motion. This is because there is reduction in height which results in a loss of potential energy and there is an increase in their speed which results in an increase in kinetic energy.

Now, immediately the skiers reaches the bottom of the hill, it means they are now at zero level height which means potential energy is now zero and it implies they have completely depleted the potential they had at the beginning at the top of the hill.

In contrast, at this zero level height, their speed and kinetic energy would have reached a maximum and this kinetic energy state will be maintained until they encounter a section of unpacked snow where they have to skid to a stop under force of friction. This friction force will carry out work on the skiers which will make their total mechanical energy to decrease. This means that as the force of friction keeps acting over an increasing distance, the quantity of work will therefore increase while the mechanical energy of the skiers will gradually be dissipated.

Eventually, the skiers will run out of energy and comes to a rest position and therefore they wouldn't be able to go as high as they first were before pushing off from the gate.

Answer:

D

Explanation:

The atmosphere is made up of constituents not chemically combined unlike the rest of the options...

The atmosphere is made up of O2, N2, etc. and they are not chemically combined, hence the atmosphere is a mixture

Answer:

m = 1.35 kg

Explanation:

       [tex]U_{i} + K_{i} = U_{f} + K_{f} (1)[/tex]

        [tex]U = \frac{1}{2} * k * \Delta x^{2} (2)[/tex]

        where k is the spring constant = 60.0 N/m, and Δx is the distance from

        the equilibrium  position.

        [tex]\frac{1}{2} * k *\Delta x_{i} ^{2} =\frac{1}{2} * k *\Delta x_{f} ^{2} +\frac{1}{2} * m *v ^{2} (3)[/tex]

       m =1.35 kg

Answer: True

Explanation: I took the quiz and got it right! have a great day.

True, tornadoes are accompanied by spinning downdrafts and updrafts that form a funnel cloud.

What is a Tornado?

A tornado can be defined as a spinning air column, usually violet resulting from a thunderstorm in the cloud and extends to the ground.

These tornadoes are accompanied by spinning downdrafts and updrafts that form a funnel cloud.

The major constituent of tornadoes are:

Thus, we can conclude that the given statement about tornadoes is true.

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200 m

We are given:

Initial velocity of the plane (u) = 0 m/s

Final velocity of the plane (v) = 40 m/s

Time interval (t) = 10 seconds

Displacement of the plane (s) = x m

Solving for x:

Acceleration of the plane

v = u + at                                                     [First equation of motion]

40 = 0 + a(10)                                              [replacing known variables]

a = 4 m/s²                                                    [dividing both sides by 10]

Displacement of the Plane:

s = ut + 1/2 (at²)                                            [Second equation of motion]

s = (0)(10) + 1/2(4)(10)²                                  [replacing known variables]

s = 200 m

Hence, the Plane covers a distance of 200 m in the given time interval

Answer:

P = 2893.95 [kPa]

Explanation:

The manometric pressure can be calculated by means of the following equation.

[tex]P=Ro*g*h[/tex]

where:

Ro = density of the water = 1000 [kg/m³]

g = gravity acceleration = 9.81 [m/s²]

h = deep = 295 [m]

Now replacing:

[tex]P = 1000*9.81*295\\P = 2893950 [Pa]\\P = 2893.95 [kPa][/tex]

Answer:

a=5 m/s^2

Explanation:

just took a quiz about it and got it right

Answer:

two-slit interference model was proposed by Young     d sin θ = m λ

Explanation:

The two-slit interference model was proposed by Young, it establishes that if a coherent source of light passes through two slits, the shape of the given pattern is a consequence of the relative phase difference between the two rays; mathematically it can be expressed by

           d sin θ = m λ

          m= 0, 1, 2, 3, ...

for constructive interference, that is, the two rays arrive with a number between wavelengths.

D is the distance between the slits, tea the angle between the two rays, m an integer and m the wavelength used.

In a simulation a pattern of slits of equal intensity and equally spaced is observed.

Answer:

A

Explanation:

m = 80 kg

a = 1.67 m/s^2

The mass is the same anywhere in the universe. So Bubba will be 80 kg anywhere. That makes A and C the only possible answers.

F = Weight = m * a

F = 80 * 1.67

F = 134 N

The answer is A

Answer:

480.2 m

Explanation:

The following data were obtained from the question:

Speed of sound (v) = 343 m/s.

Time (t) = 2.8 s

Distance (x) of the cliff =?

The distance of the cliff from the woman can be obtained as follow:

v = 2x /t

343 = 2x /2.8

Cross multiply

2x = 343 × 2.8

2x = 960.4

Divide both side by the coefficient of x i.e 2

x = 960.4/2

x = 480.2 m

Therefore, the cliff is 480.2 m away from the woman.

The distance should be 480.2 m

Since A woman standing before a cliff claps her hands, and 2.8s later she hears the echo. And, there is the velocity of 343 m/s

[tex]v = 2x \div t\\\\343 = 2x \div 2.8\\\\2x = 343 \times 2.8[/tex]

2x = 960.4

x = 480.2 m

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Answer:

Explanation:

Step one:

given data

mass of bicycle m=100kg

the velocity of bicyle v=?

mass of car M=1500kg

the velocity of car V=1.0m/s

Step two:

we know that the momentum is expressed as

P=mv

since the momentum of the bicycle must be equal to car then

mv=MV---------1

100*v=1500*1

divide both sides by 100

v=1500/100

v=15m/s

The velocity of the bicycle should be 15m/s

Acceleration of an object is the force divided by its mass. Hence, acceleration of the 100 Kg box with an applied force of 550 N is 5.5 m/s².

Acceleration is a physical quantity having both magnitude and direction. This vector measures the rate of change of velocity of a moving body. Thus, acceleration has the unit of m/s².

According to Newton's second law of motion, force acting on a body  is the product of its mass and acceleration. Thus, force is directly proportional to the mass and acceleration of the body.

Given the mass of the box = 100 Kg

 Force applied on it = 550 N.

Acceleration = 550 N / 100 Kg

                      = 5.5 m/s² ( 1 N  = 1 Kg m/s²)

Therefore, the acceleration of the box is 5.5 m/s².

To find more on acceleration, refer here:

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#SPJ2

Explanation:

ok sooooooooooo Hydropower is fueled by water so it's a clean fuel source, meaning it won't pollute the air like power plants that burn fossil fuels.

Answer:

v(t) = 2Ht - F

Explanation:

Since, the position of the object is given in terms of time (t) as follows:

x(t) = Ht² - Ft + G

where,

H, F, G are constants.

Therefore, the velocity of the object can also be found in terms of the time (t), by simply taking the derivative of the given position equation with respect to time. So, the velocity can be found as follows:

(d/dt) x(t) = (d/dt)(Ht² - Ft + G)

v(t) = (d/dt)(Ht²) - (d/dt)(Ft) + (d/dt)(G)

v(t) = H (d/dt)(t²) - F (d/dt)(t) + (d/dt)(G)

v(t) = H(2t) - F(1) + 0

v(t) = 2Ht - F

Answer:

Explanation:

Rate of flow of liquid through a tube can be expressed by the following expression

V = π P r⁴ / 8ηl

P is pressure difference between end of tube = 618 Pa

r , radius of tube = .5 x 10⁻²

η is viscosity of liquid flowing = .63  

l is length of tube = .10 m

V = 3.14 x 618 x (  .5 x 10⁻² )⁴ / (8 x .63 x .10 )

= 240.64 x 10⁻⁸ m³ /s

mass = 240.64 x 1260 x 10⁻⁸ kg / s

= 3.03 x 10⁻³ kg /s

= 3.03 gram /s .

Answer:

[tex]\displaystyle x=10\sqrt{3}\ m/s[/tex]

[tex]y=10\ m/s[/tex]

Explanation:

Rectangular coordinates of vectors in 2D

Given a vector with a magnitude v and angle θ with respect to the positive horizontal direction, the x and y components of the vector are given by:

[tex]x=v\cos\theta[/tex]

[tex]y=v\sin\theta[/tex]

The soccer ball is kicked upward at an angle θ = 30° and at a speed v=20 m/s.

The rectangular components of the vector are:

[tex]x=20\cos 30^\circ[/tex]

[tex]\displaystyle x=20\cdot \frac{\sqrt{3}}{2}[/tex]

Operating:

[tex]\mathbf{\displaystyle x=10\sqrt{3}\ m/s}[/tex]

[tex]y=20\sin 30^\circ[/tex]

[tex]\displaystyle y=20\cdot \frac{1}{2}[/tex]

Operating:

[tex]\mathbf{y=10\ m/s}[/tex]

Answer:

[tex]v=\sqrt{26}~m/s[/tex]

Explanation:

Parametric Equation of the Velocity

Given the position of the particle at any time t as

[tex]r(t) = (x(t),y(t))[/tex]

The instantaneous velocity is the first derivative of the position:

[tex]v(t)=(v_x(t),v_y(t))=(x'(t),y'(t))[/tex]

The speed can be calculated as the magnitude of the velocity:

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

We are given the coordinates of the position of a particle as:

[tex]x=5t-3t^2[/tex]

[tex]y=5t[/tex]

The coordinates of the velocity are:

[tex]v_x(t)=(5t-3t^2)'=5-6t[/tex]

[tex]v_y(t)=(5t)'=5[/tex]

Evaluating at t=1 s:

[tex]v_x(1)=5-6(1)=-1[/tex]

[tex]v_y(1)=5[/tex]

The velocity is:

[tex]v=\sqrt{(-1)^2+5^2}[/tex]

[tex]v=\sqrt{1+25}[/tex]

[tex]\mathbf{v=\sqrt{26}~m/s}[/tex]

Answer:

v = 0.4 m/s

Explanation:

       [tex]v_{avg} = \frac{x_{f}-x_{o}}{t_{f} -t_{o}} (1)[/tex]

       [tex]v_{avg} = \frac{x_{f}}{t_{f} }} (2)[/tex]

       [tex]v_{avg} =\frac{x_{f}}{t_{f} } = \frac{4.0m}{10s} = 0.4 m/s (3)[/tex]