Compare and contrast how sound waves behave when they

encounter solid hard surfaces
encounter soft surfaces
pass through an opening
encounter a barrier

Answer:

The cost is 297 cents.

Explanation:

Power of iron, P = 1140 W

Power of coffee pot, P' = 510 W

Voltage, V = 110 V

Time, t = 0.5 h each day

Cost = 12 cents per kWh

(a) Total energy

E = P x t + P' x t

E = 1140 x 0.5 x 60 x 60 + 510 x 0.5 x 60 x 60

E = 2052000 + 918000 = 2970000 J

1 kWh = 3.6 x 10^6 J

E = 0.825 kWh

For 30 days

E' = 0.825 x 30 = 24.75 kWh

So, the cost is

= 12 x 24.75 = 297 cents

Answer:

a) Nonconservative Work

[tex]W_{disp} = 9\,J[/tex]

Final Gravitational Potential Energy

[tex]U_{f} = 0\,J[/tex]

Final Translational Energy

[tex]K_{f} = 35.131\,J[/tex]

b) Nonconservative Work

[tex]W_{disp} = 6.5\,J[/tex]

Final Gravitational Potential Energy

[tex]U_{f} = 12.259\,J[/tex]

Final Translational Energy

[tex]K_{f} = 25.373\,J[/tex]

c) Nonconservative Work

[tex]W_{disp} = 4\,J[/tex]

Final Gravitational Potential Energy

[tex]U_{f} = 24.518\,J[/tex]

Final Translational Energy

[tex]K_{f} = 15.614\,J[/tex]

Explanation:

The nonconservative work due to water resistance is defined by definition of work:

[tex]W_{disp} = F\cdot (y_{o}-y_{f})[/tex] (1)

Where:

[tex]W_{disp}[/tex] - Dissipate work, in joules.

[tex]F[/tex] - Resistance force, in newtons.

[tex]y_{o}[/tex] - Initial height, in meters.

[tex]y_{f}[/tex] - Final height, in meters.

The final gravitational potential energy ([tex]U_{f}[/tex]), in joules, is calculated by means of the definition of gravitational potential energy:

[tex]U_{f} = m\cdot g\cdot y_{f}[/tex] (2)

Where:

[tex]m[/tex] - Mass of the rock, in kilograms.

[tex]g[/tex] - Gravitational acceleration, in meters per square second.

The final translational kinetic energy ([tex]K_{f}[/tex]), in joules, is obtained by means of the Principle of Energy Conservation, Work-Energy Theorem and definitions of gravitational potential energy and translational kinetic energy:

[tex]m\cdot g\cdot y_{o} = U_{f} + K_{f} + W_{disp}[/tex] (3)

[tex]K_{f} = m\cdot g\cdot y_{o} - U_{f} - W_{disp}[/tex]

Lastly, the mechanical energy of the system ([tex]E[/tex]), in joules, is the sum of final gravitational potential energy, translational kinetic energy and dissipated work due to water resistance:

[tex]E = U_{f} + K_{f} + W_{disp}[/tex] (4)

Now we proceed to solve the exercise in each case:

a) Nonconservative Work ([tex]F = 5\,N[/tex], [tex]y_{o} = 1.8\,m[/tex], [tex]y_{f} = 0\,m[/tex])

[tex]W_{disp} = (5\,N)\cdot (1.8\,m - 0\,m)[/tex]

[tex]W_{disp} = 9\,J[/tex]

Final Gravitational Potential Energy ([tex]m = 2.5\,kg[/tex], [tex]g = 9.807\,\frac{m}{s^{2}}[/tex], [tex]y_{f} = 0\,m[/tex])

[tex]U_{f} = (2.5\,kg) \cdot \left(9.807\,\frac{m}{s^{2}}\right)\cdot (0\,m)[/tex]

[tex]U_{f} = 0\,J[/tex]

Final Translational Energy ([tex]m = 2.5\,kg[/tex], [tex]g = 9.807\,\frac{m}{s^{2}}[/tex], [tex]y_{o} = 1.8\,m[/tex], [tex]U_{f} = 0\,J[/tex], [tex]W_{disp} = 9\,J[/tex])

[tex]K_{f} = (2.5\,kg)\cdot \left(9.807\,\frac{m}{s^{2}} \right)\cdot (1.8\,m) -0\,J-9\,J[/tex]

[tex]K_{f} = 35.131\,J[/tex]

b) Nonconservative Work ([tex]F = 5\,N[/tex], [tex]y_{o} = 1.8\,m[/tex], [tex]y_{f} = 0.50\,m[/tex])

[tex]W_{disp} = (5\,N)\cdot (1.8\,m - 0.5\,m)[/tex]

[tex]W_{disp} = 6.5\,J[/tex]

Final Gravitational Potential Energy ([tex]m = 2.5\,kg[/tex], [tex]g = 9.807\,\frac{m}{s^{2}}[/tex], [tex]y_{f} = 0.5\,m[/tex])

[tex]U_{f} = (2.5\,kg) \cdot \left(9.807\,\frac{m}{s^{2}}\right)\cdot (0.5\,m)[/tex]

[tex]U_{f} = 12.259\,J[/tex]

Final Translational Energy ([tex]m = 2.5\,kg[/tex], [tex]g = 9.807\,\frac{m}{s^{2}}[/tex], [tex]y_{o} = 1.8\,m[/tex], [tex]U_{f} = 12.259\,J[/tex], [tex]W_{disp} = 6.5\,J[/tex])

[tex]K_{f} = (2.5\,kg)\cdot \left(9.807\,\frac{m}{s^{2}} \right)\cdot (1.8\,m) -12.259\,J-6.5\,J[/tex]

[tex]K_{f} = 25.373\,J[/tex]

c) Nonconservative Work ([tex]F = 5\,N[/tex], [tex]y_{o} = 1.8\,m[/tex], [tex]y_{f} = 1\,m[/tex])

[tex]W_{disp} = (5\,N)\cdot (1.8\,m - 1\,m)[/tex]

[tex]W_{disp} = 4\,J[/tex]

Final Gravitational Potential Energy ([tex]m = 2.5\,kg[/tex], [tex]g = 9.807\,\frac{m}{s^{2}}[/tex], [tex]y_{f} = 1\,m[/tex])

[tex]U_{f} = (2.5\,kg) \cdot \left(9.807\,\frac{m}{s^{2}}\right)\cdot (1\,m)[/tex]

[tex]U_{f} = 24.518\,J[/tex]

Final Translational Energy ([tex]m = 2.5\,kg[/tex], [tex]g = 9.807\,\frac{m}{s^{2}}[/tex], [tex]y_{o} = 1.8\,m[/tex], [tex]U_{f} = 24.518\,J[/tex], [tex]W_{disp} = 4\,J[/tex])

[tex]K_{f} = (2.5\,kg)\cdot \left(9.807\,\frac{m}{s^{2}} \right)\cdot (1.8\,m) -24.518\,J-4\,J[/tex]

[tex]K_{f} = 15.614\,J[/tex]

Explanation:

Given that,

The length of the blades, l = 53 m

The angular velocity = 14 rpm = 1.466 rad/s

(a) The speed at the tip of a blade.

[tex]v=r\omega\\\\=53\times 1.466\\\\=77.69\ m/s[/tex]

(b) The centripetal acceleration at the tip of the blade is :

[tex]a=\dfrac{v^2}{r}\\\\a=\dfrac{77.69^2}{53}\\\\a=113.88\ m/s^2[/tex]

Hence, this is the required solution.

Answer:

the resulting angular acceleration is 15.65 rad/s²

Explanation:

Given the data in the question;

force generated in the patellar tendon F = 400 N

patellar tendon attaches to the tibia at a 20° angle 3 cm( 0.03 m ) from the axis of rotation at the knee.

so Torque produced by the knee will be;

T = F × d⊥

T = 400 N × 0.03 m × sin( 20° )

T = 400 N × 0.03 m × 0.342

T = 4.104 N.m

Now, we determine the moment of inertia of the knee

I = mk²

given that; the lower leg and foot have a combined mass of 4.2kg and a given radius of gyration of 25 cm ( 0.25 m )

we substitute

I = 4.2 kg × ( 0.25 m )²

I = 4.2 kg × 0.0626 m²

I = 0.2625 kg.m²

So from the relation of Moment of inertia, Torque and angular acceleration;

T = I∝

we make angular acceleration ∝, subject of the formula

∝ = T / I

we substitute

∝ = 4.104 / 0.2625

∝ = 15.65 rad/s²

Therefore, the resulting angular acceleration is 15.65 rad/s²

Answer:

Force = Mass × Acceleration

[tex]{ \tt{force = 2250 \times 4.3}} \\ = { \tt{9675 \: newtons}}[/tex]

Explanation:

The sum of the voltages of the components connected in a series circuit is equal to the voltage across the battery.

[tex]V_T = V_1 + V_2 +V_3[/tex]

From Ohm's law ([tex]V=IR[/tex]) and in a series circuit, the amount of current flowing through the components is the same for all. So we can write [tex]V_T[/tex] as

[tex]V_T= 75\:\text{V} = I(170)+I(190) + 21\:\text{V}[/tex]

[tex]I(170+190)=54\:\text{V}[/tex]

[tex]I= \dfrac{54\:\text{V}}{360\:\text{ohms}}=0.15\:\text{A}[/tex]

Answer:

c

Explanation:

i think the answer is c because the acceleration is directly proportional to the force but inversely proportional to the mass of the body according to the equation

a=f/m

hope this helps

Answer:

See image

Explanation:

Plato

Answer:

?

Explanation:

i am sorry but there is no triangle

Explanation: edmentum sample answer

Answer:

BFSkinner enfatizó la importancia de   creía en la importancia de desarrollar la psicología experimental y dejar atrás el psicoanálisis y las teorías acerca de la mente basadas en el simple sentido común.

Explanation:

Answer:

Simple harmonic motion is the movement of a body or an object to and from an equilibrium position. In a simple harmonic motion, the maximum displacement (also called the amplitude) on one side of the equilibrium position is equal to the maximum displacement.

The force acting on an object must satisfy Hooke's law for the object to undergo simple harmonic motion. The law states that the force must be directed always towards the equilibrium position and also directly proportional to the distance from this position.

In order to achieve the condition of simple harmonic motion, the force must be directed always towards the equilibrium position and also directly proportional to the distance from this position.

The given problem is based on the concept and fundamentals of simple harmonic motion. Simple harmonic motion is the movement of a body or an object to and from an equilibrium position.

Thus, we can conclude that in order to achieve the condition of simple harmonic motion, the force must be directed always towards the equilibrium position and also directly proportional to the distance from this position.

Learn more about the Simple Harmonic motion here:

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Answer:

Distance from sun, orbit and rotation. Presence of interior oceans, and elements that forms compressed water.

Explanation:

Answer:

The capacitance of a parallel plate capacitor is the quantity of charge the capacitor can hold.

This capacitance is proportional to the area of the any of the two plates (if the area of the plates are the same), or the smaller of the two plates (if the plates have different areas) and inversely proportional to the square of the distance of separation (or thickness of the dielectric material) between the plates. It is mathematically expressed as;

C = Aε₀ / d

Where;

C = capacitance

A = Area of one of the plates.

d = distance between the plates

Some of the applications of capacitance (or simply a capacitor) in an electric circuit are;

i. For storage of electrostatic energy.

ii. For filtering and tuning of circuits.

Answer:

[tex]\omega=109.67\ rad/s[/tex]

Explanation:

Given that,

The speed of the ball, u = 34 m/s

The ball is 0.310 m from the elbow joint.

We need to find the angular velocity (in rad/s) of the forearm.

We know that,

[tex]v=r\omega\\\\\omega=\dfrac{v}{r}\\\\\omega=\dfrac{34}{0.31}\\\\\omega=109.67\ rad/s[/tex]

So, the required angular velocity of the forearm is 109.67 rad/s.

Answer:

1.Emitted primarily through the burning of fossil fuels (oil, natural gas, and coal), solid waste, and trees and wood products. Changes in land use also play a role. Deforestation and soil degradation add carbon dioxide to the atmosphere, while forest regrowth takes it out of the atmosphere.

2.Acid rain is caused by a chemical reaction that begins when compounds like sulfur dioxide and nitrogen oxides are released into the air. These substances can rise very high into the atmosphere, where they mix and react with water, oxygen, and other chemicals to form more acidic pollutants, known as acid rain.

3.Untreated, heat exhaustion can lead to heatstroke, a life-threatening condition that occurs when your core body temperature reaches 104 F (40 C) or higher. Heatstroke requires immediate medical attention to prevent permanent damage to your brain and other vital organs that can result in death.

4.The loss of solar energy in passing through the atmospheric layers is called the atmospheric deflection. ... The longer the path traversed, the greater the amount of radiant energy depleted. Various processes whereby heat energy is lost through the atmosphere are known as scattering, diffusion, absorption, and reflection.

5.Geothermal energy is renewable because the Earth has retained a huge amount of the heat energy that was generated during formation of the planet. In addition, heat is continuously produced by decay of radioactive elements within the Earth. The amount of heat within the Earth, and the amount that is lost though natural processes (e.g. volcanic activity, conduction/radiation to the atmosphere), are much, much more than the amount of heat lost through geothermal energy production. At any one geothermal field, however, the temperature of the geothermal reservoir or the fluid levels/fluid pressure in the reservoir may decrease over time as fluids are produced and energy is extracted. Produced fluids can be re-injected to maintain pressures, although this may further cool down the reservoir if care is not taken. Over time, it is commonly necessary to drill additional wells in order to maintain energy production as temperatures and/or reservoir fluid pressures decline.

6.Floods, Floodplains, and Flood-Prone Areas. ... Flooding is a result of heavy or continuous rainfall exceeding the absorptive capacity of soil and the flow capacity of rivers, streams, and coastal areas. This causes a watercourse to overflow its banks onto adjacent lands.

The environmental concerns associated with the production of electricity are the release of greenhouse gases, the release of gases that cause acid rain, the release of excess heat, the flooding of land, and the depletion of geothermal energy so, option C is correct.

The presence or movement of charged particles is electricity. The movement of electrons through a circuit is known as an electric current. The accumulation of electrons on an insulator causes static electricity.

Mostly released when solid trash, trees, and wood products are burned, along with fossil fuels (coal, gas, and oil).

Land use changes also have an impact. Carbon dioxide is released into the atmosphere by deforestation and soil erosion, while it is removed from it by forest regeneration.

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#SPJ2

The height of the motorcycle daredevil when it reaches the landing ramp is 4.93 m.

Since the ramp is a 33.0° ramp and the motorcycle daredevil jumps off with a speed of 20.3 m/s, the motorcycle dare devil has a horizontal component of speed u = 20.3cos33.0° m/s and a vertical component of speed v = 20.3sin33.0° m/s.

Now, since the other ramp is d = 28.0 m away, it takes the time it takes the motorcycle dare devil to reach it is t.

Considering motion in the horizontal direction, d = ut.

Thus, t = d/u

= 28.0 m/20.3cos33.0° m/s

= 28.0 m/(20.3 × 0.8387) m/s

= 28.0 m/17.025 m/s

= 1.645 s

Let h be the height of the motorcycle daredevil when it reaches the landing ramp in time, t.

Considering the vertical motion and using h = vt - 1/2gt² where v = vertical velocity of motorcycle daredevil = 20.3sin33.0°, t = time taken to reach landing ramp = 1.645 s and g = acceleration due to gravity = 9.8 m/s² (Note that there is a negative in front of g since it is directed downwards)

So, substituting the values of the variables into the equation, we have

h = vt - 1/2gt²

h = 20.3sin33.0° m/s × 1.645 s - 1/2 × 9.8 m/s² × (1.645 s)²  

h = 20.3 × 0.5446 m/s × 1.645 s - 1/2 × 9.8 m/s² × 2.706025 s²

h = 18.187 m - 1/2 × 26.519 m

h = 18.187 m - 13.26 m

h = 4.927

h ≅ 4.93 m

So, the height of the motorcycle daredevil when it reaches the landing ramp is 4.93 m.

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Answer:

α = 1930.2 rad/s²

Explanation:

The angular acceleration can be found by using the third equation of motion:

[tex]2\alpha \theta=\omega_f^2-\omega_i^2[/tex]

where,

α = angular acceleration = ?

θ = angular displacement = (1500 rev)(2π rad/1 rev) = 9424.78 rad

ωf = final angular speed = 0 rad/s

ωi = initial angular speed = (960 rev/s)(2π rad/1 rev) = 6031.87 rad/s

Therefore,

[tex]2\alpha(9424.78\ rad) = (0\ rad/s)^2-(6031.87\ rad/s)^2\\\\\alpha = -\frac{(6031.87\ rad/s)^2}{(2)(9424.78\ rad)}[/tex]

α = - 1930.2 rad/s²

negative sign shows deceleration

Answer:

Answer:

A beam in bending experiences tensile stresses on one side and compressive stresses on the other side.

Explanation:

Answer:

Resistance, R = 0.02 Ohms

Explanation:

Ohm's law states that at constant temperature, the current flowing in an electrical circuit is directly proportional to the voltage applied across the two points and inversely proportional to the resistance in the electrical circuit.

Mathematically, Ohm's law is given by the formula;

V = IR

Where;

V is the voltage or potential difference.

I is the current.

R is the resistance.

From the attachment, we would pick the following values on the graph of current against voltage;

Voltage, V = 0.5 V

Current = 25 A

To find resistance;

R = V/I

R = 0.5/2.5

Resistance, R = 0.02 Ohms

Note:

Resistance (R) is the inverse of slope i.e change in current with respect to change in voltage.

Answer:

The answer is "Option C".

Explanation:

It's evident from the figure below that after thirty minutes, not no more hydrogen can be created because all of the reactants have converted into products.

hydrogen gas created in cm cubes per period x = 20 seconds, y = 45 centimeters squared, and so on.

A reaction's terminus (the graph's flat line) indicates that no further products are being created during the reaction.

Answer:

a

Explanation:

Answer:

The force of the floor on his shoes is bigger than his weight.

Explanation:

From Newton's third law of motion which states that to every action there is an equal an opposite reaction, we can say that the ground exerts additional force on the basketball player, thereby overcoming his weight and pushing him off the ground.

So, when the basketball player jumps, his muscles contract or extend appropriately which in turn creates an additional force on the ground. Hence, the force of the floor on his shoes is bigger than his weight.

Answer:

True

Explanation:

This is true because the current occurs in the galvanometer not because the t coil that acts as a transformer or because it's ferromagnetic but because of the galvanometer records a current because the free electrons in the moving wire experience a force from the magnetic field that pushes them through the wire.

Answer:

A) ΔV = 1.237 V

B) K.E = 1.237 eV

Explanation:

B)

The initial kinetic energy of the electron is given by the following formula:

[tex]K.E = \frac{1}{2}mv^2\\\\[/tex]

where,

K.E = Kinetic Energy of electron = ?

m = mass of elctron = 9.1 x 10⁻³¹ kg

v = speed of electron = 660000 m/s

Therefore,

[tex]K.E = \frac{1}{2}(9.1\ x\ 10^{-31}\ kg)(660000\ m/s)^2[/tex]

K.E = 1.98 x 10⁻¹⁹ J

K.E = (1.98 x 10⁻¹⁹ J)([tex]\frac{1\ eV}{1.6\ x\ 10^{-19}\ J}[/tex])

K.E = 1.237 eV

A)

The energy applied by the potential difference must be equal to the kinetic energy of the electron, in order to stop it:

[tex]e\Delta V = K.E\\\\\Delta V = \frac{K.E}{e}[/tex]

where,

e = charge on electron = 1.6 x 10⁻¹⁹ C

Therefore,

[tex]\Delta V = \frac{1.98\ x\ 10^{-19}\ J}{1.6\ x\ 10^{-19}\ C}[/tex]

ΔV = 1.237 V

Answer:

resistor R₂ has the lowest current density

Explanation:

The current density is

          j = I / A

now let's analyze each case

a) R₂ has an area 2A₀ and a length L₀ that R₁

b) R₃ has an area Ao and a length 3L₀ what R₁

we can see that all the area is given in relation to the resistance R₁

the current density in R₁ is

         j₁ = I / A₀

the current density in R₂

         j₂ = I / 2A₀

         j₂ 2 = ½ I/A₀

the current density in R₃

         j₃ = I / A₀

         j₂ < j₁ = j₃

therefore resistor R₂ has the lowest current density

Answer:

The ball moves from lowest to highest point:

W = M g h = 3 * 9.8 * 4 = 118 J

This is work done "against" gravity so work done by gravity is -118 J

The tension of the string does no work because the tension does not

move thru any distance   W = T * x = 0 because the length of the string is fixed.

Answer:

Following are the response to the given question:

Explanation:

To address this problem, the notions of friction and torque in the kinematic equations of motion have to be applied.

The friction resistance is defined by

[tex]F=\mu mg[/tex]

Here seem to be our values.

[tex]\mu=0.3\\\\m= 120\ kg \\\\g=9.8\ \frac{m}{s^2} \\\\[/tex]

[tex]F=0.3 \times 120 \times 9.8= 36 \times 9.8= 352.8 \ N[/tex]

Take the brain's mid-size weight halfway to the floor, i.e. [tex]d = \frac{0.85}{2} = 0.425 \ m[/tex]. The torque around the bottom of the cooler should be zero to reach the maximum range.

[tex]F \times x= mg \times d\\\\ \text{Re-set for x}\\\\ x=\frac{mg \times d}{F}= \frac{mg \times d}{ \mu m g} =\frac{d}{\mu}=\frac{0.425}{0.3}=1.42 \m[/tex]

Then we may say that distance before turning is 1.42m.

Answer:

b. approaches zero.

Explanation:

The phenomenon is known as length contraction.

Length contraction is a result of Einstein's special theory of relativity. This theory states that an observer in an inertial frame of reference will observe a decrease in the length of any moving object placed at another inertial frame of reference.

let the length of the train = L

Let the length observed when the train is in motion = L₀

Apply Einstein's special theory of relativity;

[tex]L_0 = L \times \sqrt{1 - \frac{v^2}{c^2} } \\\\where;\\\\v \ is \ the \ velocity \ of \ the \ train\\\\c \ is \ the \ speed \ of \ light\\\\[/tex]

from the equation above, when v = 0, the length observed is equal to the initial length of the train. (L₀ = L)

As the velocity of the train (v) approaches the speed of light (c), the length of the train observed (L₀) becomes smaller than the initial length of the train (L).  (L₀ < L)

Eventually, when v equals c, we will have a square root of zero (0), and the length observed will become zero.  (L₀ = 0)

Thus, the length of this object, as measured by a stationary observer approaches zero

Answer:

AN ELASTIC COLLISION IS SAFER

Explanation:

IT'S BECAUSE THE MOVEMENT IS PRESERVED. YEN AN ELASTIC

COLLISION, THE ELASTIC BODY ABSORBS SOME OF THE MOVEMENT.

THIS CAUSES THE CAR TO SLOW DOWN MORE SLOWLY THAN IN AN

INELASTIC COLLISION WHERE IT DECELERATES FASTER.

ANYWAY I LEAVE YOU THE LINK

(THEY ALREADY DELETED THE ENGLISH SITE, BUT YOU CAN USE

TRANSLATOR):

https://gscourses.thinkific.com

Answer:

Option D. ²²²₉₀Th

Explanation:

Let the unknown be ⁿₘZ. Thus, the equation becomes:

²²⁶₉₂U —> ⁴₂He + ⁿₘZ

Next, we shall determine n, m and Z. This can be obtained as follow:

For n:

226 = 4 + n

Collect like terms

226 – 4 = n

222 = n

n = 222

For m:

92 = 2 + m

Collect like terms

92 – 2 = m

90 = m

m = 90

For Z:

ⁿₘZ => ²²²₉₀Z => ²²²₉₀Th

Therefore, the complete equation becomes:

²²⁶₉₂U —> ⁴₂He + ⁿₘZ

²²⁶₉₂U —> ⁴₂He + ²²²₉₀Th

Thus, the unknown is ²²²₉₀Th