When a person inhales, air moves down the bronchus (windpipe) at 15 cm/s. The average flow speed of the air doubles through a constriction in the bronchus. Assuming incompressible flow, determine the pressure drop in the constriction.

The electric field midway between two equal but opposite point charges is 567 N/C , and the distance between the charges is 16.0 cm.

a)What is the magnitude of the charge on each?

As defined in Chapter 7, the work done by a force on an object is equal to the force times the displacement times the cosine of the angle between the force and displacement vectors (W=F·d cos(θ)).
Suppose you are supporting a 1.56-kg block. What is the gravitational force (magnitude and direction) acting on the block?

If you lower the block a distance of 0.208 m, what is the work done by the gravitational force as you lower the block?

What is the value of the angle θ (in degrees – do not enter units)?

What is the change in the gravitational potential energy as you lower the block 0.208 m? (If the potential energy increases, the answer should be positive. If the potential energy decreases, the answer should be negative.)

Let’s switch gears and ask about the electrical force on a charged object. Suppose you have a region where the electric field has a magnitude of 23.1 N/C, the field points straight down, and the field is uniform (ie., the magnitude and direction are the same everywhere in this region). You place an object which has a charge of +0.251 C in this field. What is the magnitude and direction of the electric force acting on the object?

Suppose you lower the object a distance 0.208 m (in the same direction the field is pointing). What is the work done by the electrical force as you lower the block?

What is the change in electric potential energy as you lower the object 0.208 m? (If the electric potential energy increases, the answer should be positive. If the electric potential energy decreases, the answer should be negative.)

This discussion is closed.

A tower worker at the top of a wind turbine tower is letting down a small broken part of mass 4.3 kg tied to a practically massless rope.

The top of the tower is 14.4m above the ground, and the wind is blowing at 6.3 m/s at the top of the tower and decreases linearly with height to 1.7 m/s at the ground.

She is letting the rope slide thru her leather gloves at a rate of 0.30 m/s, and the friction between the rope and her gloves is making the gloves warm. What power is being

dissipated as heat where rope is sliding on the gloves?

In this problem, consider electrostatic forces only. In the figure, there is a particle of charge +Q at x = 0, and there is a particle of charge +16Q at x = +4a. You are going to bring in a third particle, with a charge of ?4Q, and place it at an appropriate spot on the x-axis. Use Q = 60.0 ? 10^?6C, and a = 40.0 cm. Also, use k = 9.00 ? 10⁹ N · m²/C².

(a)First, place the particle of charge ?4Q at the correct location so that the +Q charge experiences no net force because of the other two charged particles. In that situation, calculate the magnitude of the force that just one of the other charged particles exerts on the +Q charge.

(b)Instead, at what location on the x-axis would you place the particle of charge ?4Q so that the +16Q charge experiences no net force because of the other two charged particles? Note that we're looking for an answer in units of centimeters.

(c)Finally, place the particle of charge ?4Q at the correct location so that the ?4Q charge experiences no net force because of the other two charged particles. In that situation, calculate the magnitude of the force that just one of the other charged particles exerts on the ?4Q charge.

Explain the phenomenon of induction that was studied in this activity (bringing a negatively charged plastic rod near an uncharged non-metal-coated styrofoam ball that is hanging freely and an uncharged metal-coated styrofoam ball that is hanging). For example, explain how a metal conductor such as a hanging ball of aluminum foil can be attarcted to a charged insulator even though the ball of foil has no net charge so that is is electrically neutral. Can two metal balls with no net charge attract each other? Explain. Can the process of induction cause a neutral conductor to be repelled from a charged insulator? Explain.

Thank you very much :)

Three vectors are given as A=<3.5, -5.3, 1.1> B=<4.5, 7.5, -7> C=<-3.9, 4.8, -6>

a) Determine the angle between A and B.

b) Determine the angle between A and C

c) Compute the dot product of B and C

d) Determine the size of the area associated with vectors B and C.

e) Determine the quantity (B (dot)(A(cross)C))

Two horizontal metal plates, each 10.0 cm square, are aligned 1.00 cm apart with one above the other. They are given equal-magnitude charges of opposite sign so that a uniform downward electric field of 1.96 103 N/C exists in the region between them. A particle of mass 2.00 10-16 kg and with a positive charge of 1.09 10-6 C leaves the center of the bottom negative plate with an initial speed of 1.04 105 m/s at an angle of 37.0° above the horizontal. (c) Where does it strike, relative to its starting point? (Enter the horizontal distance from the initial position.)

1 (a) Assume that the lights in your kitchen use 300 watts. How much energy and how much does it cost to leave the lights on 24 hours a day for a week if electricity is 8 cents/kilowatt hour?

(b) For a month (assume 30 days/month)?

(c) For a year?

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2 (a) How much energy and how much money do you use to run your window air conditioner rated at 1500 watts continuously for the month of July (assume 8¢/kWh)?

(b) If you assume that coal was used to produce the electricity for your air conditioner, how much coal was burned to produce the electricity used?

(c) How much CO2 was produced by the electricity used to run your air conditioner?

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3 (a) An average incandescent light bulb has a life expectancy of 1,000 hours. How much energy would a typical 60 watt bulb use in a lifetime, assuming it lasts for 1,000 hours?

(b) At 8¢/kWh, how much would it cost over its lifetime?

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4 (a) A compact fluorescent bulb uses 15 watts and has a life expectancy of 10,000 hours. How much energy and how much would it cost to use a compact fluorescent for 10,000 hours?

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5 (a) If your car gets 20 miles per gallon (MPG), and you drive an average of 10,000 miles each year, how many gallons of gas do you use a year?

(b) At $3.00 per gallon, how much will you spend on gasoline for the year?

(c) If the combustion of each gallon of gasoline produces 22 lbs of CO2, how much CO2 does your car produce each year?

(d) If you traded your car in & bought one that got 25 MPG, how much gasoline would you save in one year?

(e) How much money would you save?

(f) How much less CO2 would be emitted into the atmosphere from your improved car?

A damped oscillator has a frequency w' that is 10% less than its undamped frequency. a) By what factor is the amplitude of the oscillation decreased during each oscillation? b) By what factor is its energy reduced during each oscillation.

A 0.5530-kg ice cube at -12.40°C is placed inside a chamber of steam at 365.0°C. Later, you notice that the ice cube has completely melted into a puddle of water. If the chamber initially contained 6.790 moles of steam (water) molecules before the ice is added, calculate the final temperature of the puddle once it settled to equilibrium. (Assume the chamber walls are sufficiently flexible to allow the system to remain isobaric and consider thermal losses/gains from the chamber walls as negligible.) Use the following values for the heat capacities of ice, water and steam Ice=2093 J/(kg x C) Water=4186 J/(kg x C) Steam= 2009 J/(kg x C)

Research 4 types of technology that we have in our world that are related to either magnetism or electromagnetism. The technology can be directly related to these topics or just a snowball effect and only somewhat related to them.
Yo should include:
3 examples of technology
Explanation how the technology helps humans (or will help them in future)
Explanation how the tecnology is related to magnetism or electromagnetism

An infinite line of charge with linear density λ₁ = 7.2 μC/m is positioned along the axis of a thick insulating shell of inner radius a = 2.2 cm and outer radius b = 4.1 cm. The insulating shell is uniformly charged with a volume density of ρ = -562 μC/m³.

1) a) What is λ₂, the linear charge density of the insulating shell?____μC/m

b) What is E_x(P), the value of the x-component of the electric field at point P, located a distance 7.9 cm along the y-axis from the line of charge?____N/C

c) What is E_y(P), the value of the y-component of the electric field at point P, located a distance 7.9 cm along the y-axis from the line of charge?___N/C

d) What is E_x(R), the value of the x-component of the electric field at point R, located a distance 1.1 cm along a line that makes an angle of 30^o with the x-axis?_____N/C

e) What is E_y(R), the value of the y-component of the electric field at point R, located a distance 1.1 cm along a line that makes an angle of 30^o with the x-axis?____N/C

f) For how many values of r: (2.2 cm < r < 4.1 cm) is the magnitude of the electric field equal to 0?

none

one

more than one

g) If we were to double λ₁ (λ₁ = 14.4 μC/m), how would E, the magnitude of the electric field at point P, change?

E would double

E would increase by more than a factor of two

E increases by less than a factor of two

E decreases by less than a factor of two

E decreases by more than a factor of two

h) In order to produce an electric field of zero at some point r > 4.1 cm, how would λ₁ have to change?

Change its sign and increase its magnitude

Change its sign and decrease its magnitude

Keep its sign the same and increase its magnitude

Keep its sign the same and decrease its magnitude

1). Indicate whether the object will remain in circular motion or not for each case below. Show a calculation as proof. If it doesn’t stay in circular motion, state what happens to it.

a). A car traveling at a speed of 24 m/s around an unbanked curve with a radius of curvature of 108 m and a coefficient of static friction of 0.36 .

b). A person riding in a roller coaster car as it goes over the top of a curve with a radius of curvature of 33 m at a speed of 16 m/s.