Ultrasound is:

a
of lower frequency than the human ear can detect.

b
the speed at which the latest, top-secret jet aircraft fly.

c
used to make internal images of the human body.

d
extremely painful to the human ear.

Answer:

A) Z-1

Explanation:

when a radioactive element of atomic number Z emits an alpha particle, the mass of the new nucleus decreases by 2, i.e the new atomic number of the element = ( Z- 2).

Also, when the daughter nucleus emits a beta particle, the new nucleus increases by 1,  that is the new atomic number of the element = (Z + 1).

Thus, the atomic number of resulting nuclide = Z ( - 2) + ( + 1).

                                                                           = Z - 2 + 1

                                                                           = Z - 1

Therefore, the atomic number of resulting nuclide is Z - 1

Answer:

Angular speed = 27.78 rad/s (Approx)

Explanation:

Given:

Diameter = 21.6 cm

Speed = 3 m/s

Find:

Angular speed

Computation:

Radius = 21.6 / 2 = 10.8 cm = 0.108 m

Angular speed = v / r

Angular speed = 3 / 0.108

Angular speed = 27.78 rad/s (Approx)

Answer:

12445 J

Explanation:

Given that

Power output, P = 5 kW

efficiency of the engine, e = 27% = 0.27

Thermal energy expelled, Q(c) = 9085 J

Heat absorbed, Q(h) = ?

Using the formula

e = W/Q(h)

e = [Q(h) - Q(c)] / Q(h)

e = 1 - Q(c)/Q(h)

Now, substituting the values into the formula, we have

0.27 = 1 - 9085/Q(h)

9085/Q(h) = 1 - 0.27

9085/Q(h) = 0.73

Q(h) = 9085 / 0.73

Q(h) = 12445 J

Thus, the heat absorbed is 12445 J

Answer:

1.) 7.3 m/s 2.) 6.1 m/s

Explanation:

To calculate the initial horizontal velocity with just degrees and velocity alone is pretty simple. The formula is     Velocity*cos(degrees)

eg 9.5*cos(40)

2.  To calculate the initial vertical velocity with just degrees and velocity alone is pretty simple. The formula Velocity*sin(degrees)

eg 9.5*sin(40)

Complete Question

A certain refrigerator, operating between temperatures of -8.00°C and +23.2°C, can be approximated as a Carnot refrigerator.

What is the refrigerator's coefficient of performance? COP

(b) What If? What would be the coefficient of performance if the refrigerator (operating between the same temperatures) was instead used as a heat pump? COP

Answer:

a

 [tex]COP = 8.49[/tex]

b

  [tex]COP_1 = 9.49[/tex]  

Explanation:

From the question we are told that

     The lower operation temperature of refrigerator is  [tex]T_1 = -8.00^oC = 265 \ K[/tex]

     The upper operation temperature of the refrigerator is   [tex]T_2 = 23.2 ^oC = 296.2 \ K[/tex]

Generally the refrigerators coefficient of performance is mathematically represented as

        [tex]COP = \frac{T_1}{T_2 - T_1 }[/tex]

=>     [tex]COP = \frac{265}{296.2 - 265 }[/tex]

=>     [tex]COP = 8.49[/tex]

Generally if a refrigerator (operating between the same temperatures) was instead used as a heat pump , the coefficient of performance is mathematically represented as

            [tex]COP_1 = \frac{T_2}{ T_2 - T_1}[/tex]  

=>         [tex]COP_1 = \frac{296.2}{ 296.2 - 265 }[/tex]  

=>         [tex]COP_1 = 9.49[/tex]  

The coefficient of performance if the refrigerator is used as a heat pump is 9.5.

The given parameters;

The coefficient of performance if the refrigerator is used as a heat pump is calculated as follows;

[tex]COP = \frac{T_2}{T_2 - T_1}\\\\COP = \frac{296.2}{296.2 - 265} \\\\COP =9.5[/tex]

Thus, the coefficient of performance if the refrigerator is used as a heat pump is 9.5.

"Your question is not complete, it seems to be missing the following information";

A certain refrigerator, operating between temperatures of -8.00°C and +23.2°C, can be approximated as a Carnot refrigerator.

What would be the coefficient of performance if the refrigerator (operating between the same temperatures) was instead used as a heat pump?

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The awnser is sulfur dioxide.

The gas that is responsible for lowering the temperature is sulfur dioxide gas.

A volcanic eruption refers to the sudden escape of lava and gases from the earth's core. It usually occurs at a very high temperature. The solidification of the volcano leads to rock formation.

During a volcanic eruption, the gas that is responsible for lowering the temperature is sulfur dioxide gas.

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By conservation of momentum :

[tex]m_1u_1 + m_2u_2 = m_1v_1 + m_2v_2\\\\96v + 0 = 96v_1 + 135\times 1.03\\\\96v = 96v_1 +139.05 \ \ \ \ \ \ .....1[/tex]

By conservation of energy :

[tex]\dfrac{m_1u_1^2}{2}+\dfrac{m_1u_2^2}{2} =\dfrac{m_2v_1^2}{2} +\dfrac{m_2v_2^2}{2}\\\\96v^2 + 0 = 96v_1^2 + 135(1.03)^2\\\\96v^2 = 96v_1^2 +143.22 \ \ \ \ \ ....2)[/tex]

Solving equation 1 and 2, we get :

v = 1.23 m/s

Therefore, the initial speed of 96 kg car is 1.23 m/s .

Answer:

roughly 8-10 hours for the average human being

Explanation:

its A or D but im not sure which one ik it moves fast

Unclear/incomplete question. However, I inferred you need an explanation of the phenomenon of rainfall​.

Explanation:

Basically, the phenomenon of rainfall​ follows a natural cycle called the water cycle. What we call 'rainfall' occurs when water condensed (in liquid form) in the atmosphere is made to fall down on the ground as tiny droplets as a result of the forces of gravity.

The water cycle makes rainfall possible:

Answer:

-240

Explanation:

A motorcycle skids for a distance of 2.0 m on an icy road, then the change in kinetic energy for the motorcycle will be equal to -240 J.

The force which a moving object has is referred to as kinetic energy in physics. It is defined as the number of effort required to propel a person of a specific mass from still to a specific velocity.

Aside from slight fluctuations in speed, your body holds onto the kinetic energy it obtains during acceleration.

When the body slows down from its present level to a condition of rest, the same quantity of energy is used.

Formally, kinetic energy is any quantity that has a gradient concerning time in the Lagrangian of a system.

As per the given information in the question,

Distance, d = 2.0 m

Friction, f = 120 N

The angle between displacement and friction force, θ = 180°

Now, the change in kinetic energy for the motorcycle = Work done by the friction.

K.E = f × d(cos θ)

= 120 (2.0 m)(cos 180°)

Δ K.E = -240 J

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Answer:

Explanation:

The potential energy of a body can be found by using the formula

PE = mgh

where

m is the mass

h is the height

g is the acceleration due to gravity which is 9.8 m/s²

PE = 10 × 9.8 × 20

We have the final answer as

Hope this helps you

Answer a

Explanation: a

The exercise involves filling in the gaps with the possible wave

properties that can be obtained from a spring.

The correctly completed exercise is presented as follows;

A wave is a disturbance that moves through a medium. There are two

types of waves. A mechanical wave requires matter to travel. List some

examples of this type: sound wave, water wave, spring waves.

A electromagnetic wave does not require a medium. Examples include: Light waves

In order to start and transmit a mechanical wave, a source of

disturbance and a physical medium are required. A single disturbance is

referred to as a pulse, and a series of disturbance is a wave train.

This type of wave is called transverse wave. Its pulses are called crest

and troughs.

Now send a pulse by quickly pushing the spring forward and pulling it

back, as shown. This type of wave is called longitudinal wave. Watch the

motion of the ribbon. In this type, the particles move parallel to the

direction the wave travels. Its pulses are called compression and

rarefactions. Note that all waves transfer energy without transferring

matter. In mechanical waves, particle of the medium vibrate back and

forth in simple harmonic motion while the disturbance (or energy)

moves from one place to another.

B. Wave speed

Does the pulse catch up to the other? yes. The size of the pulse is called

the amplitude of the wave.

Did the size of the pulse affect the speed? No.

The average time wave it takes the wave to travel

Without changing your positions therefore keeping the distance the

pulse travels the same), pull the slinky tighter using only about 3/4 of

coils. This makes a completely different medium through which the

pulse will travel. Time the journey as before time record. Does the kind

of medium affect the speed of the pulse? Yes

C. Wavelength and Frequency

High frequency waves have short wavelengths and low frequency waves

have long wavelengths.

The speed of a wave in any medium is equal to the frequency of the wave × the wavelength. This wave equation [tex]\underline{f = \dfrac{v}{\lambda } }[/tex] shows that f and λ are

inversely proportional. The units of the variables are;

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(a) When the kinetic energy of an electron is transformed into potential energy is when it interacts with other electrons, decreasing its speed.

(b)  The region of atoms that interact in bonds is electric fields of particles with negative charge.

(c) Initial repulsion is low and increases as they approach.

(d) The force between the charges is 562.5 N.

This theory states that, the collision of particles (electrons) of matter is perfectly elastic. This implies that as the particles (electrons) collides with one another, kinetic energy is transferred from one electron to another.

ΔK.E = ΔP.E

Change in kinetic energy is equal to change in potential energy of the electrons.

Thus, when the kinetic energy of an electron is transformed into potential energy is when it interacts with other electrons, decreasing its speed. Decrease in speed implies decrease in kinetic energy and increase in potential energy.

Chemical bond is formed from the transfer or sharing of electrons between atoms. (electrons between atoms implies negative charge to negative charge)

Thus, the region of atoms that interact in bonds is electric fields of particles with negative charge.

This law states that the force of attraction or repulsion between two charges is directly proportional to the product of the charges and inversely proportional to the distance between the charges.

[tex]F = \frac{kq_1q_2}{r^2}[/tex]

When the distance between the electrons are large, the repulsive force is low and the distance is small, the repulsive force is high.

The force between the charges is determined by applying Coulomb's law,

[tex]F = \frac{kq_1q_2}{r^2} \\\\F = \frac{9\times 10^9\times (5 \times 10^{-5}) \times (2\times 10^{-6})}{0.04^2} \\\\F = 562.5 \ N[/tex]

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Answer:

816

Explanation:

We must remember that torque is defined as the product of a force by a distance.

This distance is measured from the pivot point of the Bolt to the point where the force is applied. in this way, we have the following equation to be able to determine the torque.

[tex]T=F*d[/tex]

Now if we double the turning distance we have the torque should also be double.

[tex]T =F*2*d[/tex]

Answer:

radation because the heat gets too intense and is forced to rise

Given :

Brandon hits a golf ball with an initial velocity of 30 m/s at an angle of 30 above the horizontal.

To Find :

How long is it in the air.

Solution :

We know, the formula of time of flight is :

[tex]T = \dfrac{2usin\ \theta}{g}\\\\T = \dfrac{2\times 30\times sin\ 30^o}{9.8}\\\\T = 3.06\ seconds[/tex]

Therefore, the ball is in air for 3.06 seconds.

Answer:ratio of the radii of their orbits = 1.3 --- C

Explanation:

1- eV = to the kinetic energy of the electrons

and kinetic energy is given as

K.E= 1/2mv2

v = √(2E/m)----- equation 1

The force on the particles  relating to the magnetic and circular motion ( centripetal force is given as

F = magnetic force = centripetal force

F= qvB = mv2/r

qvB = mv2/r

  r = mv/qB ------ equation 2

We know from equation 1 that v = √(2E/m)

Therefore,

r = √(2mE)/qB------ equation 3

We can now say that the  ratio of the two radii of their orbits can be calculated as

r1/r2 =(√(2mE1)/qB) /(√(2mE2)/qB

Where E1 = 500-eV  and E2 = 300-eV (1- eV = to the kinetic energy of the electrons)

r1/r2 = (√(2m x500)/qB) /(√(2mx 300)/qB

Cancelling out common variables, we are left with

r1/r2 =[tex]\sqrt{500/300}[/tex]

r1/r2= 1.29 ≈ 1.3

Answer:

[tex]MA = 3[/tex]

Explanation:

Given

[tex]Box = 10kg[/tex]

[tex]Ramp\ Height = 5ft[/tex]

[tex]Ramp\ Length = 15ft[/tex]

Required

Determine the mechanical advantage

This is calculated as follows:

[tex]MA = \frac{Ramp\ Length}{Ramp\ Height}[/tex]

[tex]MA = \frac{15ft}{5ft}[/tex]

[tex]MA = 3[/tex]

Hence, the mechanical advantage is 3

Given :

The decibel scale intensity for busy traffic is 80 dB.

Two people having a loud conversation have a decibel intensity of 70 dB.

To Find :

The approximate combined sound intensity.

Solution :

We know, intensity in decibel can be converted to W/m² by :

[tex]\beta(dB) = 10\ log_{10}( \dfrac{I}{I_o})[/tex]

Putting intensity in decibel scale, we get :

[tex]I(80\ dB ) =10^{-4}\ W/m^2\\\\I(70\ dB ) = 10^{-5}\ W/m^2[/tex]

Let, combine intensity is I .

I = I(80 dB) + I(70 dB)

[tex]I = 10^{-4} + 10^{-5} \ W/m^2\\\\I = 1.1 \times 10^{-4} \ W/m^2[/tex]

Therefore, the combined sound intensity is [tex]1.1 \times 10^{-4} \ W/m^2[/tex] .

Answer:

C) 600 Hz

Explanation:

The fundamental frequency can be related to the driving frequency by the expression below;

f(n) = n * f(1)

Where f(1)= fundamental frequency

f(n) = driving frequency

There are four equal segments in the standing wave , then our n= 4 and our f(n)=4, then we can get the fundamental frequency here

f(4) = 4× f(1)

480 = 4× f(1)

f(1) = 480/4

f(1)=120Hz

Hence, fundamental frequency is 120Hz

To calculate the driving frequency that will set up a standing wave with five equal segments?

n=5

f(n) = n× 120Hz

f(5) = 5×120Hz

= 600Hz.

Hence, the driving frequency that will set up a standing wave with five equal segments is 600Hz

Answer: 75 N to the right

Explanation:

When two forces acting in opposite directions, they will cancel in magnitudes. Here, the net force acting on the table is 75 N to the right.

Force is an external agent acting on an object to change its motion or to deform it. Force is a vector quantity. Hence, it is characterized by a magnitude and direction.

If two equal forces are acting on object from the same direction, they will add up in magnitudes and the net force is their sum. If the two forces are from opposite directions, they will cancel each other in magnitude and the net force will be the substracted value.

Here, Bill is pulling by 250 N to the left and Janet is pulling to the right by 325 N. The force is not balanced because they are unequal.

net force = 325 - 250 = 75 N

The larger force is to the right. Hence, the net force is 75 N to the right.

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Answer:

Your average speed is 60 kilometers per hour

Explanation:

240 divided by 4 is 60

240/4=60

Answer:

The value is  [tex]\mu_k = 0.102[/tex]

Explanation:

From the question we are told that

   The initial speed of the pluck is  [tex]u = 10 \ m/s[/tex]

    The  distance it slides on the horizontal ice is  [tex]s = 50 \ m[/tex]

Generally from kinematic equation we have that

       [tex]v^2 = u^2 + 2as[/tex]      

Here v is  is the final velocity and the value is 0 m/s given that the pluck came to rest, so

      [tex]0^2 = 10 ^2 + 2* a * 50[/tex]      

=>   [tex]a = - 1 \ m/s^2[/tex]

Here the negative sign show that the pluck is decelerating  

 Generally the force applied on the pluck is  equal to the frictional force experienced by the pluck

      So  

                [tex]F = F_f[/tex]

=>            [tex]m * a = m* g * \mu_k[/tex]

=>             [tex]1 = 9.8 * \mu_k[/tex]

=>              [tex]\mu_k = 0.102[/tex]

Answer:

the gravitational force decreases

The speed and displacement are 6.66 m/s and 10 blocks east, respectively. The total distance traveled is larger than the displacement between those two points if an object changes direction while traveling.

Displacement: Is it a distance?

Sometimes people mistakenly believe that distance and displacement are simply two different labels for the same thing. Displacement and distance, however, are two distinct ideas. The overall distance traveled by an object during its voyage will be larger than the displacement if it changes direction.

What does displacement mean in one sentence?

The smallest (straight line) distance between a body's initial location and its final position—represented by an arrow pointing from the starting position to the final position—is referred to as a body's displacement when it moves from one position to another.

Briefing:

speed=10/1.5

         =6.66m/s

displacement=10 block toward east.

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Answer:

Vs/c = 20 [m/s]

Explanation:

This is a problem of relative velocities, as velocity is a vector we can use addition or subtraction of vectors for the solution.

We are asked for the velocity of the sailboat with respect to an observer located in the canoe.

[tex]V_{s/c}=V_{sailboat}-V_{canoe}\\V_{s/c}=15-(-5)\\V_{s/c}=20[m/s][/tex]

Why is the speed of the canoe negative?, it is negative because the canoe moves in the opposite direction to the sailboat.