3)When a power source like a battery is connected to a circuit, an electric field pushes electrons within the conducting wires causing them to flow. The electric field exists due to an uneven build up of charge on the surfaces of the wires (called a surface charge gradient). In this set of problems we will explore a simple model of how this all comes about and emphasize the connection between source charges, electric fields, and voltage differences in the context of electric circuits.

A very small segment of the conducting wire in a circuit can be modeled as a circular ring of radius 1 mm. Consider two such rings surrounding the z-axis separated by a small distance 2 mm. Let's first suppose that both rings have the same charge density. What is the strength of the electric field on the z-axis at the midpoint between the two rings?

4)If you used a voltmeter to measure the voltage difference between the centers of the two rings, what measurement would you read?

In: Physics

3) A soccer ball is kicked with an initial horizontal speed of 8 m/s and an initial vertical speed of 6

m/s. Identify the following quantities and include one short sentence to explain your answer using

the concepts of projectile motion (no calculations are necessary). Assume that projection and

landing height are the same and neglecting air resistance (4 pts):

a) The ball’s horizontal speed 0.5 seconds into its flight is:

because:

b) The ball’s horizontal speed midway through its flight is:

because:

c) The ball’s horizontal speed immediately before contact with the ground is:

because:

d) The ball’s vertical displacement up is (circle one) greater than/less than/the same as the

vertical displacement down because:

e) The ball’s vertical velocity halfway through its flight is:

because:

f) The ball’s vertical speed immediately before contact with the ground is:

because:

***answer in significant digits

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A wheel with a weight of 395 N comes off a moving truck and rolls without slipping along a highway. At the bottom of a hill it is rotating at an angular velocity of 22.2 rad/s . The radius of the wheel is 0.647 m and its moment of inertia about its rotation axis is 0.800 MR2. Friction does work on the wheel as it rolls up the hill to a stop, at a height of h above the bottom of the hill; this work has a magnitude of 3524 J . Calculate h. Use 9.81 m/s2 for the acceleration due to gravity.

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Consider a spacecraft in an elliptical orbit around the earth. At the low point, or perigee, of its orbit, it is 300km above the earth's surface; at the high point, or apogee, it is 2500km above the earth's surface.

A) What is the period of the spacecraft's orbit?

B) Using conservation of angular momentum, find the ratio of the spacecraft's speed at perigee to its speed at apogee.

C) Using conservation of energy, find the speed at perigee and the speed at apogee.

Enter your answers numerically separated by a comma.

D) It is necessary to have the spacecraft escape from the earth completely. If the spacecraft's rockets are fired at perigee, by how much would the speed have to be increased to achieve this?

E) What if the rockets were fired at apogee?

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Two converging lenses with focal lengths of 40 cmand 20 cm are 10 cm apart. A 2.0 cm -tall object is 15 cm in front of the 40 cm -focal-length lens.

Calculate the image position and image height.

Please show work, thanks-

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A Geiger–Muller tube is a type of gas‑filled radiation
detector. It can detect particles like X‑rays, alpha particles, and
beta rays (electrons). This is useful in quantizing the activity of
a radioactive source or determining if an area containing
radioactive material is safe to enter. Assuming that you have 1mol
of gas, if a Geiger counter is filled with 9674 Pa of argon gas at
room temperature (T=23.3 °C), what is the density,

ρ, of the gas in this Geiger tube?

In: Physics

Physics Question:

A wheel has a radius of .5 m and a moment of inertia I = 3kg m^2. It is rotating at 20 rev/s about an ais through its center when a stick, acting as a brake, is applied to the outer edge. It is brought to rest in 30 seconds

a.) Find the angular acceleration of the wheel

b.) How many revolutions does it make before coming to rest?

c.) How much kinetic energy does it lose in coming to rest?

d.) How much force did the stick exert on the wheel?

e.) Find the linear distance covered by a speck of dust, located halfway between the center of the wheel and the outer edge, during the time the wheel was coming to rest

In: Physics

1. You made two determinations of the wavelength of the bright green mercury line, one based on the first order interference and the other based on the second order interference. Which one do you think is more precise? Explain why.

2. Why is the wavelength of the spectral lines that seem same color have slightly different wavelength when emitted by different element?

3. List some diffraction phenomena in your daily life experience.

4. What does the spectrum from sunlight look like in the spectrometer? Give your thoughts comparing the spectrum with the white light from mercury?

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A 1500 kg automobile travels at a speed of 85 km/h along a straight concrete highway. Faced with an emergency situation, the driver jams on the brakes, and the car skids to a stop.

(a) What will be the car's stopping distance for dry pavement (µ = 0.85)?

(b) What will be the car's stopping distance for wet pavement (µ = 0.60)?

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The kinetic energy of a particle is equal to the energy of a photon. The particle moves at 6.1% of the speed of light. Find the ratio of the photon wavelength to the de Broglie wavelength of the particle. Take the speed to be non-relativistic.

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A) At what angular
frequency is the voltage amplitude across the *resistor* in
an*L*-*R*-*C* series circuit at maximum
value?

(Express your answer in terms of the variables *L*,
*C*, and *R*.)

B) At what angular
frequency is the voltage amplitude across the *inductor* at
maximum value?

(Express your answer
in terms of the variables *L*, *C*, and
*R*.)

C) At what angular frequency is the voltage amplitude across the
*capacitor* at maximum value?

(Express your answer
in terms of the variables *L*, *C*, and
*R*.)

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A firehose must be able to shoot water to the top of a building
38.0 m tall when aimed straight up. Water enters this hose at a
steady rate of 0.515 m^{3}/s and shoots out of a round
nozzle.

(a) What is the maximum diameter this nozzle can have?

1 __________ cm

(b) If the only nozzle available has a diameter twice as great,
what is the highest point the water can reach?

2______________

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When the first nuclear bomb was detonated, some scientists
believed that a huge

nuclear chain reaction would occur, blowing the earth to pieces.
Calculate the energy

that would be required to disassemble the earth completely into
pieces totally

separate from each other.

In: Physics

So this is my assignment. My question is, what makes an object a good insulator? Does having a high specific heat alone make a good insulator? Water has a very high specific heat, would it make a good insulator for the material?

Please list off a bunch of common household items with why they are good insulators!

**Objective:** Construct an insulated device that
is designed to retain heat. Heated water will be put into a beaker
and the beaker will be put into the device and allowed to cool for
45 minutes.

**Construction:**

The device must fit within a 15.0 cm × 15.0 cm × 15.0 cm cube.

Devices may be constructed of and contain any materials
**except** for the following prohibited materials: any
type of foam, bubble wrap, commercial insulation, metal other than
aluminum foil.

Within the device, you must be able to insert and remove a 250 mL standard, unaltered, empty Pyrex beaker.

The device must also easily accommodate the insertion of a thermometer probe all the way through to the bottom of the beaker via a hole at least 1.5 cm in diameter.

Devices may not contain any energy sources (e.g., no electrical components, small battery powered heaters, chemical reactions, etc.) to help keep the water warm.

All parts of the device must not be significantly different from room temperature.

**Highest temperature after 45 minutes wins!**

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A baseball is hit 40 m/s at an angle of 30 degree. A 5 m high fence is 125 m away. Does it go over the fence?

In: Physics