In a container of negligible mass, 020 kg of ice at an initial temperature of - 40.0 oC is mixed with a mass m of water that has an initial temperature of 80.0 oC. No heat is lost to the surroundings. If the final temperature of the system is 20.0 oC, what is the mass m of the water that was initially at 80.0 oC

Answers

Answer 1

Answer:

The mass is  [tex]m_w = 0.599 \ kg[/tex]

Explanation:

From the question we are told that    

     The mass of ice is  [tex]m_c = 0.20 \ kg[/tex]

     The  initial temperature of the ice is  [tex]T_i = -40.0 ^oC[/tex]

     The  initial temperature of the water is  [tex]T_{iw} = 80^o C[/tex]

     The  final temperature of the system is [tex]T_f = 20^oC[/tex]

Generally according to the law of energy conservation,

   The  total heat loss is  =  total heat gained

 Now the total heat gain is mathematically represented as

      [tex]H = H_1 + H_2 + H_3[/tex]

Here  [tex]H_1[/tex] is the energy required to move the ice from [tex]-40^oC \to 0^oC[/tex]

And it mathematically evaluated as

     [tex]H_1 = m_c * c_c * \Delta T[/tex]

Here the specific heat of ice is  [tex]c_c = 2100 \ J \cdot kg^{-1} \cdot ^oC^{-1}[/tex]

So  

    [tex]H_1 = 0.20 * 2100 * (0-(-40))[/tex]  

     [tex]H_1 = 16800\ J[/tex]

[tex]H_2[/tex] is the energy to melt the ice

And it mathematically evaluated as

       [tex]H_2 = m * H_L[/tex]

The  latent heat of fusion of ice is  [tex]H_L = 334 J/g = 334 *10^{3} J /kg[/tex]

So  

    [tex]H_2 = 0.20 * 334 *10^{3}[/tex]

    [tex]H_2 = 66800 \ J[/tex]

[tex]H_3[/tex] is the energy to raise the melted ice to [tex]20^oC[/tex]

And it mathematically evaluated as

    [tex]H_3 = m_c * c_w * \Delta T[/tex]

Here the specific heat of water  is  [tex]c_w= 4190\ J \cdot kg^{-1} \cdot ^oC^{-1}[/tex]

    [tex]H_3 = 0.20 * 4190* (20-0))[/tex]  

     [tex]H_3 = 16744 \ J[/tex]  

So

  [tex]H = 16800 + 66800 + 16744[/tex]

   [tex]H = 100344\ J[/tex]

The  heat loss is mathematically evaluated as

     [tex]H_d = m * c_h ( 80 - 20 )[/tex]

     [tex]H_d = m_w * 4190 * ( 80 - 20 )[/tex]

     [tex]H_d = 167600 m_w[/tex]

So

      [tex]167600 m_w = 100344[/tex]

=> [tex]m_w = 0.599 \ kg[/tex]

     


Related Questions

When landing after a spectacular somersault, a 41 kg gymnast decelerates by pushing straight down on the mat. Calculate the force she must exert if her deceleration is 7.00 times the acceleration due to gravity. Explicitly show how you follow the steps in the Problem-Solving Strategy for Newton's laws of motion.

Answers

Answer:

The force the  gymnast  must exert is 2812.6 N.

Explanation:

Given;

mass of the gymnast, m = 41 kg

her deceleration, -a = 7g = 7 x 9.8m/s² = 68.6 m/s²

Apply Newton's second law of motion;

F = ma

where;

F is the magnitude of the force exerted

m is the mass of the gymnast

a is the deceleration

Substitute in the given values of m and a into the force equation;

F = ma

F = 41 x 68.6

F = 2812.6 N

Therefore, the force the  gymnast  must exert is 2812.6 N.

A diffraction-limited lens can focus light to a 10-μ m-diameter spot on a screen. Do the following actions make the spot diameter larger, smaller, or leave it unchanged? a. Decreasing the wavelength of light: b. Decreasing the lens diameter c. Decreasing the focal length: d. Decreasing the lens-to-screen distance:

Answers

Answer:

a) the size of the sport DECREASES  , b)the spot size is increased

c)  it has no effect  and d) spot size DECREASES

Explanation:

The expression for constructive interference in diffraction is

         a sin θ = m λ

the chaff of the spot is given by the minimum interference m = 1

           a sin θ = λ

let's use trigonometry to find the angle

         tan λ= y / L

         tan θ = sin θ / cos t = sin θ

         sin θ = y / L

          a y / L = lam

in the case of materials with circular dome, the problem must result in polar coordinates, with which a numerical constant is introduced

          y = 1.22 L / a lam

let's analyze each electrode action in this equation

a) Decrease lam

         y ’= 1.22 L / a lm2

          lam2 <lamo

          y '<y

therefore the size of the sport DECREASES

b) decreases the lens diameter

       a '<a

         y ’= 1.22 L / a’ lam

         y '> y

the spot size is increased

c) Decrease the focal length

The expression does not depend on the focal length, so it has no effect

d) decrease in L

         y ’= 1.22 L’ / a lam

spot size DECREASES

A very long straight current-carrying wire produces a magnetic field of 20 mT at a distance d from the wire. To measure a field of 5 mT due to this wire, you would have to go to a distance from the wire of
A- 4d.
B - 16d.
C - d sqrt2
D- 8d.
E- 2d.

Answers

Answer:

A. 4d

Explanation:

Magnetic field strength is inversely proportional to distance. So in order to have a smaller magnetic field, we need to move further out from the wire. How far we go exactly can be determined from the formula: B=(μ₀I)/(2πr)

(That is derived from Ampere's Law, which states ∫B•dl=μ₀I)

With that you can set up a ratio between the magnetic fields in both cases. Because the current is the same for both instances, everything reduces out on one side of the equation and leaves you with something that relates the two distances by a ratio of each magnetic field value.

My work is in the attachment, comment for questions.

The wave function for a particle must be normalizable because:________ a. the particle's angular momentum must be conserved. b. the particle cannot be in two places at the same time. c. the particle must be somewhere. d. the particle's momentum must be conserved. e. the particle's charge must be conserved

Answers

Answer:

C the particle must be somewhere.

Explanation:

This is because normalization of wave function means the maximum probability of finding a particle in a region is 1. And a Wave function describes the probability of finding a particle in region. Also Since it is a probability distribution, its integral over all space must be 1, explaining that the probability that the particle is somewhere and thus it must integrate to 1, meaning it must be it must be normalizable


Which of these particles are equal in number when an atom is neutral?
A. protons, neutrons
B. protons, electrons
C. neutrons, electrons
D. protons, neutrons, electrons

Answers

Answer: It’s A because I remember science. I know it sound dumb but it’s true

If a ball is accelerating down through the air with no horizontal motion, what must be true about the net forces acting on the ball? (a) The net force on the ball is directed upward. (b) The net force on the ball is zero. (c) The gravitational force is greater than the drag. (d) The drag is greater than the gravitational force.

Answers

Answer:

The net force on the ball is zero.

Explanation:

The net force and the acceleration on the falling skydiver is upward. An upward net force on a downward falling object would cause that object to slow down. The skydiver thus slows down. As the speed decreases, the amount of air resistance also decreases until once more the skydiver reaches a terminal velocity.A force can cause a resting object, or it can accelerate a moving object by changing the object's speed or direction. When the forces on an object are balanced, the net force is zero and there is no change in the object's motion. When an unbalanced force acts on an object, the object accelerates.

which of the following graphs shows the motion of an object that starts to travel forward, stops for several seconds, and then returns to its original position

Answers

Answer:

B

Explanation:

in graph B, you can see that the position increases and remains constant for a while before returning to 0

Mass on a Spring: A 0.150-kg air track cart is attached to an ideal spring with a force constant (spring constant) of 3.58 N/m and undergoes simple harmonic oscillations. What is the period of the oscillations

Answers

Answer:

The  period is  [tex]T = 1.286 \ s[/tex]

Explanation:

From the question we are told that

   The mass of the spring is  [tex]m = 0.150 \ kg[/tex]

   The spring constant is  [tex]k = 3.58 \ N/m[/tex]

   

Generally the  period is mathematically represented as

      [tex]T = 2 \pi \sqrt{ \frac{m}{k} }[/tex]

substituting values

     [tex]T = 2 \pi \sqrt{ \frac{ 0.150}{3.58} }[/tex]

      [tex]T = 1.286 \ s[/tex]

What is the power in a circuit that has a current of 12 amps and a resistance of 100 ohms? a. 14,400 watts b. 8.3 watts c. 144 watts d. 1200 watts

Answers

Answer:

a. 14,400 Watts

Explanation:

Power is current times voltage.

P = IV

Voltage is current times resistance.

V = IR

Substitute:

P = I²R

P = (12 A)² (100 Ω)

P = 14,400 W

A paper pinwheel is spinning in the wind. Which statement is correct about the forces responsible for the rotation?​

Answers

A paper pinwheel is spinning in the wind.

Which statement is correct about the forces responsible for the rotation?

The components of gravity and the force of wind that point through the pivot are responsible for the rotation.

Only the perpendicular component of wind is responsible for the rotation, because gravity points downward.

Only the perpendicular component of gravity is responsible for the rotation, because wind points toward the pivot.

The perpendicular components of gravity and the force of wind are responsible for the rotation.

Answer:

Only the perpendicular component of gravity is responsible for the rotation because wind points toward the pivot.

Explanation:

A pinwheel is a plaything that is made up of paper that is designed to spin when the wind comes in contact with it. The paper is held fast to its axle by a pin which enables it to spin.

Therefore, if the pinwheel is spun anti-clockwise, it brings electrical energy, converting the wind energy and only the perpendicular component of gravity is responsible for the rotation because wind points toward the pivot.

A bar of silicon is 4 cm long with a circular cross section. If the resistance of the bar is 280 Ω at room temperature, what is the cross-sectional radius of the bar?

Answers

Answer:

r = 17.05 cm

Explanation:

Given that,

Length of silicon bar is 4 cm or 0.04 m

Resistance of the bar is 280 ohms

We know that the resistivity of the silicon is 640 Ωm

We need to find the cross-sectional radius of the bar. Let it is r.

Using definition of resistance of an object. It is given by :

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

A is area of bar, A = πr²

So,

[tex]R=\rho\dfrac{l}{\pi r^2}\\\\r^2=\dfrac{\rho l}{R\pi}\\\\r^2=\dfrac{640\times 0.04}{280\pi}\\\\r=0.1705\ m\\\\r=17.05\ cm[/tex]

So, the cross-sectional radius of the bar is 17.05 cm.

When asked how to create an electromagnet, the best answer would be:

"You can create an electromagnet by applying a direct current to a non–magnetic material in order to create an electromagnetic field."
"You can create an electromagnet by covering a wire with insulation and applying a direct electrical current to the magnet."
"You can create an electromagnet by coiling a ferromagnetic material, wrapping in an insulator, and applying a current to the coil."
"You can create an electromagnet by wrapping an insulated wire around a metal with ferromagnetic properties and applying an electric current."

Answers

Answer:

"You can create an electromagnet by wrapping an insulated wire around a metal with ferromagnetic properties and applying an electric current."

Explanation:

An electromagnet is created by coiling a ferromagnetic material with the help of an insulated wire around it and applying a  current . Insulated wire carrying current produces magnetic field around it . This field produces magnetic flux in the magnetic material and makes it magnet . When we switch of current , magnetic field ceases to exist and therefore , magnetic material ceases to be a magnet .

 

Explanation:

Suppose that you measure the length of a spaceship, at rest relative to you, to be 400 m. How long will you measure it to be if it flies past you at a speed of v

Answers

Answer:

264 m

Explanation:

The complete question is

Suppose that you measure the length of a spaceship, at rest relative to you, to be 400 m. How long will you measure it to be if it flies past you at a speed of v = 0.75c

using the length contraction relationship,

[tex]l = l_{0} \sqrt{1 - \beta ^{2} }[/tex]

where [tex]\beta = \frac{v}{c}[/tex]

[tex]l[/tex] is the relativistic length

[tex]l_{0}[/tex] is the actual length = 400 m

v is the velocity of the spaceship

c is the speed of light

since v = 0.75c

v/c = 0.75

substituting, we have

[tex]l = 400 * \sqrt{1 - 0.75 ^{2} }[/tex] = 400 x 0.66 = 264 m

A positron and an electron annihilate each other upon colliding, thereby producing energy in the form of two gamma rays. Assuming that both gamma rays have the same energy (since both particles have the same mass), calculate the wavelength of the electromagnetic radiation used in pm. (1 pm = 10⁻¹² m; mass of electron (amu) = 0.000549)

Answers

Answer:

2.42631E-13m

Explanation:

First we find the mass defect

Which is m= 0-2(9.10939E-33kg)

= - 1.82188E-30kg

Now find the energy

S

E= mc²=( -18.82188E-30)(2.999792E8)²

= 1.63742E-13J

Thus energy per photon will be

1.63742E-13J/2= 8.18710E-14J

So wavelength is given as

Lambda= hc/E

= (6.62608E-34)(2.997E8)/8.18710J

= 2.42631E-13m

The wavelength of radiation used to annihilate a positron and an electron is required.

The wavelength of the electromagnetic radiation used is 2.42 pm.

The mass of positron and electron are equal

m = Mass = [tex]\dfrac{0.000549}{6.022\times 10^{26}}=9.11\times 10^{-31}\ \text{kg}[/tex]

c = Speed of light = [tex]3\times 10^{8}\ \text{m/s}[/tex]

h = Planck's constant = [tex]6.626\times 10^{-34}\ \text{Js}[/tex]

Total energy in the collision is

[tex]E_T=mc^2+mc_2\\\Rightarrow E_T=2mc^2\\\Rightarrow E_T=2\times 9.11\times 10^{-31}\times (3\times 10^{8})^2\ \text{J}[/tex]

Energy released per photon is

[tex]E=\dfrac{E_T}{2}\\\Rightarrow E=\dfrac{2\times 9.11\times 10^{-31}\times (3\times 10^{8})^2}{2}\\\Rightarrow E=9.11\times 10^{-31}\times (3\times 10^{8})^2\ \text{J}[/tex]

Energy is given by

[tex]E=\dfrac{hc}{\lambda}\\\Rightarrow \lambda=\dfrac{hc}{E}\\\Rightarrow \lambda=\dfrac{6.626\times 10^{-34}\times 3\times 10^8}{9.11\times 10^{-31}\times (3\times 10^{8})^2}\\\Rightarrow \lambda=2.42\times 10^{-12}\ \text{m}=2.42\ \text{pm}[/tex]

The wavelength of the electromagnetic radiation used is 2.42 pm.

Learn more:

https://brainly.com/question/13187526?referrer=searchResults

A uniform disk a uniform hoop and a uniform sphere are released at the same time at the top of an inclined ramp. They all roll without slipping in what order do they reach the bottom of the ramp?

a. disk hoop, sphere
b. sphere, hoop, disk
c. hoop, sphere, disk
d. sphere, disk, hoop
e. hoop, disk, sphere

Answers

Im pretty sure the answer would be A

An electon in a box absorbs light. The longest wavelength in the absorbtion spectrum is 400 nm . How long is the box

Answers

Answer:

6.03x 10^-10 m

Explanation:

Given that

E= hc/ wavelength

And also

E= h²n2/8mL²

Equating the two and if we say the transition was from energy level 1 to 2 then

E2 - E1 = h²2/(8mL²) x ( 2² - 1²) = 3h²2/(8mL²)

So

L² = 3 h lambda / (8mc)

= 3 x6.626 10^-34 kg m^2/s x 400 10^-9 m /( 8 x 9.11 x10^-31 kg x3.00 10^8 m/s)

= 36.4 x 10^-20 m^2

L = 6.03 x 10^-10 m

The length of the box that absorbs the light is;

L = 6.03 × 10^(-10) m

We are given;

Longest wavelength of spectrum; λ = 400 nm = 400 × 10^(-9) m

Now, the formula for energy of quantization is;

E = h²n²/8mL²

Also, Energy of a photon is;

E = hc/λ

Thus;

hc/λ = h²n²/8mL²

h will cancel out to give;

c/λ = hn²/8mL²

Where;

h is Planck's constant = 6.626 × 10^(-34) m².kg/s

c is speed of light = 3 × 10^(8) m/s

λ is wavelength = 400 × 10^(-9) m

L is length of box

m is mass of electron = 9.11 × 10^(-31) kg

n² is difference in energy levels = (2² - 1²) = 3

Making L the subject gives;

L = √(hn²λ/8mc)

Thus;

L = √((6.626 × 10^(-34) × 3 × 400 × 10^(-9))/(8 × 9.11 × 10^(-31) × 3 × 10^(8))

L = √(3.636663007683 × 10^(-19))

L = 6.03 × 10^(-10) m

Read more at; https://brainly.com/question/13405242

A train is travelling along a straight track at constant velocity from Western Station to Eastern station. The mile markers increase towards the east. A passenger notices that, at mile marker 25, the reading on this stopwatch is 15 minutes, and at mile marker 60, the reading on this stopwatch is 45 minutes. What is the velocity of the train in meters per second

Answers

Answer:

Explanation:

Displacement of train = 60 - 25 = 35 mile

= 35 x 1.6 = 56 km

duration of time = 45 - 15 = 30 minutes

= 30 x 60 = 1800 s

velocity of train = displacement / time

= 56 / 1800 = .03111 km /s

= 31.111 m / s

Train A is moving at 100 kmh–1 through a station. Train B is also travelling at 100 kmh–1 through the station but in the opposite direction to train A. What is the speed of a seated passenger on? (a) train A relative to an observer on the station? (b) train A relative to another seated passenger on the same train? (c) train B relative to a passenger on train A?

Answers

Explanation:

(a) An observer on the station has a speed of 0 km/h.  The speed of  a passenger on Train A is 100 km/h.  The relative speed is 100 km/h − 0 km/h = 100 km/h.

(b) The speed of both passengers is 100 km/h, in the same direction.  The relative speed is 100 km/h − 100 km/h = 0 km/h.

(c) The speed of both passengers is 100 km/h, in opposite directions.  The relative speed is 100 km/h − (-100 km/h) = 200 km/h.

A tank 20 m deep and 7m wide is layered with 8m of oil,6m of water and 5m of mercury.complete total hydroatatic force.(density of oil and mercury is 800 and 13600kg/m respectively ).​

Answers

Answer:

F = 3.03 10⁷ N

Explanation:

We will eat by calculating the pressure in the tank

         P = ρ g h

the pressure totals the sum of the pressure of each liquid

       P_total = P_oil + P_water + P_Hg

       P_total = ρ_oil ​​g h_oil + ρ_water g h_water + ρ_Hg g h_Hg

       P_total = g (ρ_oil ​​h_oil + ρ_water h_water + ρ_Hg h_Hg)

       P_total = 9.8 (800 8 + 1000 6 + 13 600 5)

        P_total = 7,879 10⁵ Pa

The definition of Pressure is

       P = F / A

        F = P A

The area of ​​a tank is the area of ​​a circle

       A = π r² = π d² / 4

       

      F = P π d² / 4

let's calculate

      F = 7,879 10⁵ π 7²/4

      F = 3.03 10⁷ N

In this calculation the atmospheric pressure was not taken into account because they ask the hydrostatic pressure

plz solve this. plz plz plz plz simple machine ​

Answers

Answer:

Explanation:

i.  CW moment = 10 N (10 cm) + 30 N (30 cm) - 60 N (40 cm) = - 1400 N-cm

ii.  ACW momenet = 60 N (40 cm) - 10 N (10 cm) + 30 N (30 cm) = 1400 N-cm

iii.  No. The lever is not balanced in the situation. Because the moment is ± 1400 N-cm.  if balance, the moment must be Zero.

iv.   the location of 10N by keeping the other loads unchanged to balance the lever is 150 cm

take moment from Δ (support)

60(40) = 10(x) + 30(30)

2400 = 10x + 900

10x = 2400 - 900

10x = 1500

x = 1500/10

x = 150 cm  

therefore, the location of 10N by keeping the other loads unchanged to balance the lever is 150 cm

Two identical balls are thrown directly upward, ball A at speed v and ball B at speed 2v, and they feel no air resistance. Which statement about these balls is correct

Answers

Answer:

B) Ball B will go four times as high as ball A because it had four times the initial kinetic energy.

Explanation:

The complete question is

Two identical balls are thrown directly upward, ball A at speed v and boll B at speed 2v. and they feel no air resistance. Which statement about these balls is correct? A) Ball B will go twice as high as ball A because it had twice the initial speed. B) Ball B will go four times as high as ball A because it had four times the initial kinetic energy. C) The balls will reach the same height because they have the same mass and the same acceleration. D) At its highest point, ball B will have twice as much gravitational potential energy as ball A because it started out moving twice as fast. E) At their highest point, the acceleration of each ball is instantaneously equal to zero because they stop for an instant.

According to conservation of energy, the mechanical energy of a ball thrown up is equal to the sum of the potential energy and the kinetic energy. At its highest point, all the mechanical energy will be equal to the potential energy. At the instant when it was thrown, all the mechanical energy is proportional to its kinetic energy, which will be proportional to the potential energy at the highest point. Also, potential energy is proportional to the maximum height reached.

We know that the kinetic energy is given as [tex]\frac{1}{2}mv^{2}[/tex]

where

m is the mass of the balls, which is the same for both ball,

and v is the velocity.

We can see that the kinetic energy is proportional to the square of the initial velocity with which the ball is thrown.

For the ball A thrown with velocity v, the kinetic energy is proportional to [tex]v^{2}[/tex],

and for the ball B with velocity 2v, kinetic energy is proportional to [tex]4v^{2}[/tex]

comparing the two, we'll see that the ball B will had 4 times the energy of ball A. Therefore ball B will go four times as high as ball A because it had four times the initial kinetic energy

Two cars collide head on while each is traveling at 60km/h .Suppose all their kinetic energy is transformed into the thermal energy of the wrecks. What is the temperature increase of each car?You can assume that each car's specific heat is that of iron.

Answers

Answer:

The  temperature rise [tex]\Delta T = 0.3088 \ ^oC[/tex]

Explanation:

From the question we are told that

  The  speed is  [tex]v = 60 \ km /h = 16.67 \ m/s[/tex]

 

Generally according to the law of energy conservation we have that

   The  kinetic energy  =  increase in the internal energy of the car

i,e          [tex]\frac{1}{2} * m * v^2 = m * c_p * \Delta T[/tex]

Here  [tex]c_p[/tex] of  iron is  [tex]c_p = 450 \ J/kg K[/tex]

      So  

            [tex]0.5 * 16.67^2 = 450 * \Delta T[/tex]

=>         [tex]\Delta T = 0.3088 \ ^oC[/tex]

     

The temperature increase of each car will be 0.3088 °C.

What is temperature?

Temperature directs to the hotness or coldness of a body. In clear terms, it is the method of finding the kinetic energy of particles within an entity. Faster the motion of particles more the temperature.

The given data in the problem is;

v is the velocity= 60 km/h=16.67 m/sec

ΔT is the temperature difference=?

[tex]\rm c_P[/tex] is the specific heat of iron=450 J/KgK

From the law of energy conservation of the energy, the kinetic energy is equal to the increase in the internal energy of the car.

[tex]\rm KE=\triangle E \\\\\ \frac{1}{2} mv^2=mc_p \triangle T \\\\ \triangle T=\frac{v^2}{2C_p} \\\\\ \triangle T=\frac{(16.67)^2}{2\times 450} \\\\ \triangle T=0.3088 ^0\C[/tex]

Hence the temperature increase of each car will be 0.3088 °C.

To learn more about the temperature refer to the link;

https://brainly.com/question/7510619Δ

You throw a balloon that floats in the air with a velocity of 2 m / s south . If the wind speed is 5 m / s west , how far south will the balloon travel after 2 seconds ?

Answers

Answer:

The distance traveled by the balloon is 10.77 m

Explanation:

velocity of the ball, [tex]v_b[/tex] = 2 m/s south

velocity of the air, [tex]v_a[/tex] = 5 m/s west

To determine the distance the balloon will travel after 2 seconds, first determine the resultant velocity of the balloon.

                                       | 2m/s

                                       |

                                       |

                                      ↓

      5m/s  ←------------------

the two velocities forms a right angled triangle and the resultant will be the hypotenuses side of the triangle.

R² = 5² + 2²

R² = 29

R = √29

R = 5.385 m/s

The distance traveled by the balloon is calculated as;

d = R x t

where;

t is time of the motion = 2 seconds

d = 5.385 x 2

d = 10.77 m

Therefore, the distance traveled by the balloon is 10.77 m.

What is a property of “normal force”? a. It always points perpendicular to the contact surface. b. It always points parallel to the contact surface. c. It always points up. d. It always completely counters gravity.

Answers

Answer:

a. It always points perpendicular to the contact surface.

Explanation:

"Normal" means perpendicular.  Normal forces are always perpendicular to the contact surface.

An 8-hour exposure to a sound intensity level of 90.0 dB may cause hearing damage. What energy in joules falls on a 0.800-cm-diameter eardrum so exposed?

Answers

Answer:

1.4E-3J

Explanation:

Given that

Time = 8hrs = 28.8E3 seconds

Intensity= 90dB

D= 0.008m

Radius= 0.004m

So intensity is sound level Bis

10dBlog(I/Io)

I= 10 (B/10dB)Io

= 10( 90/10) x 10^-12

=0.001W/m²

But we know that

I = P/A

P= I πr²

= 5.02 x10^-8W

But energy is power x time

So E= 5.02E-8 x 28.8E3

= 1.4E-3J

Answer:

1.44x10⁻³J

Explanation:

Given :

Time = 8hrs *(3600secs/1hr)= 28.8*10³seconds

Intensity= 90dB

D= 0.008m

Radius=0.008m/2

=0.004m

the sound level in decibel can be expressed below as

I=10dBlog[I/I₀]

where I₀=10⁻¹²/m² which is the refrence intensity

90=10log[I/10⁻¹²]

I=0.001W/m²

we know that intensity of the wave which id the average rate per unit area which energy is transfered can be calculated using below formular

I = P/A

where P= powerr which is renergy transfer at a time

A= area= πr²

making P subject of formular we have

P= I πr²

= 5.02 x10⁻⁸W

Energy =power x time

E=28800*5*10⁻⁸

=0.001443J

therefore,the energy in joules is 1.44x10⁻³J

In a double slit experiment, the intensity of light at the center of the central bright fringe is measured to be 6.2 µW/m2. What is the intensity half

Answers

Answer:

   I_FWHW = 3.2 μW / m²

Explanation:

In the analysis of optics and electricity a very useful magnitude is the width at half height (FWHW) and the intensity at this height, which is given by

               I_FWHW = I₀ / 2

corresponds to the width of the line for this intensity.

In this case they give the maximum intensity for which

               I_FWHW = 6.2 / 2

               I_FWHW = 3.2 μW / m²

You do not give more data in your exercise, but the most interesting calculation is to find the angle values ​​for which you have this intensity since it is this range is 50% of the energy of the system, have I write the equation for this calculation

             I = Io cos² x₁   (sin x / x)²

             x₁ = π d sin θ /λ

             x = π b sin θ /λ

where d is the separation of the slits and b the width of each slit

how far must he mirror mz of the michelson interferometer be moved so that 1600 fringes of laser light move across a line int he field of view

Answers

Answer:

The question is not complete. Let me explain Michelson interferometer and how to calculate a question like this.

Answer 4.85 * [tex]10^{-4}[/tex]m

Explanation:

The Michelson Interferometer is an instrument which produces interference fringes by splitting a light beam into two parts, it then recombines them after they have travelled different optical paths.

The formula to measure the minute displacement is Δd=m * λ[tex]_{0}[/tex]/2

where m is the number of fringes passing a given point as the movable plane mirror is moved

and λ[tex]_{0}[/tex] is the monochromatic lamp of wavelength

In the question, m = 1600. Let us assume that the wavelength is 606 nm

Solution

Δd=m * λ[tex]_{0}[/tex]/2

Δd=1600 * 606nm/2 = 1600 * 303nm = 484800nm

We convert the nm to m (nm / [tex]10^{-9}[/tex])

4.85 * [tex]10^{-4}[/tex]m

Given 1ft = 12in, how many feet are in 36 inches?

Answers

Answer:

Hey there!

1 ft= 12 inches

3 ft= 36 inches.

Let me know if this helps :)

Answer: 3

The formula is to divide by 12

36÷12=3

1ft = 12in

An organ pipe open at both ends has two successive harmonics with frequencies of 220 Hz and 240 Hz. What is the length of the pipe? The speed of sound is 343 m/s in air.

Answers

Answer:

The  value is  [tex]l = 8.58 \ m[/tex]

Explanation:

From the question we are told that

  The  frequencies of two successive harmonics  is  [tex]f_ a = 220 \ Hz[/tex] , [tex]f_b = 240 \ Hz[/tex]

   The  speed of sound in the air is  [tex]v = 343 \ m/s[/tex]

Generally a harmonic frequency is mathematically represented as

        [tex]f_n = \frac{n * v }{2l}[/tex]

here l is the length of the pipe

n is the order of position of the harmonics

 Now since we do not know the order of the given harmonic frequencies but we are told that they are successive then the frequencies can be mathematically represented as

     [tex]220 = \frac{n * v}{ 2 l }[/tex]

and

     [tex]240 = \frac{ (n+1 ) v }{2l}[/tex]

So  

    [tex]240 - 220 = \frac{ (n+1 ) v }{2l} - \frac{n * v}{ 2 l }[/tex]

   [tex]20 = \frac{v}{2l}[/tex]

=>   [tex]l = 8.58 \ m[/tex]

Two resistors connected in parallel, with R1 = 150 ohms and R2 = 75 ohms, are connected to a battery that experiences a current of 0.18 A. The current through R1 is _____ A.

Answers

Answer:

Explanation:

Given:

Two resistors (Parallel)

R1 = 150 ohms

R2 = 75 ohm

Current (I) = 0.18 A

Find:

Current through R1

Computation:

Common resistance

1/R = 1/R1 + 1/R2

1/R = 1/150 + 1/ 75

R = 50 ohms

V = IR

V = 0.18 x 50

V = 9v

So,

V = IR1

9 = I (150)

Current through R1 = 9 / 150

Current through R1 = 0.06 A

Other Questions
Capital Budgeting Criteria: Mutually exclusive ProjectsA firm with a WACC of 10% is considering the following mutually exclusive projects:Project A Project B1 - $400 - $6002 $55 $3003 $55 $3004 $55 $505 $225 $506 $225 $49Which project would you recommend? Explain. What is the value of the expression 10 (n minus 6) when n = 14?465680134 If Na was to form a 2 ion, from what orbital subshell would the second electron be lost? which nation uses the most geothermal power A: POLAND B: AUSTRIA C: GREENLAND D: ICELAND Cooking is her hobby". What is the finite verb in the sentence? * Hernandez Corporation purchases a building for $300,000 cash. The building was appraised at $310,000. The tax assessment on the building was $280,000. Three months after purchasing the building, Company Z offers Hernandez $320,000 for the building. At what amount should the building be reported in Hernandez's financial statements according to the historical cost principle somebody plz come in clutch Evaluate Algebraic ExpressionsThe classroom is divided into four equal parts. The area of each part is 5.3 meters. What is the are of the classroom? Jennifer earns $17.35 per hour at her job. She works 6 hours per day, 5 days per week. What is Jennifers gross income for a 2 week pay period? Which of the following statements are true about segments in a plane? Choose all that apply. Every segment has infinitely many midpoints Every segment has two bisectors Every segment has one perpendicular bisector Every segment has infinitely many congruent segments Every segment has one line that is perpendicular to it What type of trauma triage criteria regarding transport would a finger amputation receive?A. Any hospital w/ surgical facilitiesB. Any hospital as long as online medical direction approves the facilities capabilities.C. Trauma centerD. The patients choice of destination 3. Shaking hands is not appropriate for a business setting in Latin America.ciertoO falso Explain why you cannot find the intersection points of the two lines shown below. Give both an algebraic reason and a graphical reason. y=4x+1 and y= 4x+10 Do all bacteria cause food to go bad and become uneatable? How does Calchas's vision advance the plot of the play? Answer choices for the above question A.It leads Odysseus to devise a plan to trick the Trojans. B.It encourages Sinon to volunteer to stay outside the city of Troy. C.It convinces Agamemnon that the city of Troy must be taken by force. D.It foreshadows Cassandra's prophecy that the Trojan Horse is a trick. m+1/4d=7 explain your answer Which statement is true? Integers are always whole numbers or all whole numbers are rational or integers include all rational members or rational numbers do not include integers. Let un be the nth Fibonacci number. Prove that the Euclidean algorithm takes precisely n steps to prove that gcd(un+1, un) = 1. Tell me what you think about technology and what you think about math, write a paragraph. The shift from mass marketing to targeted marketing, and the corresponding use of a larger, richer mix of communication channels and promotion tools ________.