If you have ever hiked or climbed to high altitudes in the mountains, you surely have noticed how short of breath you get. This occurs because the air is thinner, so each breath contains fewer O2 molecules than at sea level. At the top of Mt. Everest, the pressure is only 13atm. Air contains 21.0 % O2 and 78.0 % N2, and an average human breath is 0.480 L of air.

Part A) At the top of Mt. Everest, how many O2 molecules does each breath contain when the temperature is -10.0 ∘F?

Express your answer as number of molecules.

Part B) What percent is this of the number of O2 molecules you would get from a breath at sea level at -10.0 ∘F?

Express your answer as a percentage.

A new printed circuit board design for a high speed electronic oscillator seems to fail at high frequencies. Your job is to double check the design. One part of the circuit consists of two rectangular loops, the smaller one centered inside the larger one. Both rectangles have their long sides in the same direction. The smaller rectangle has long sides of length ℓ and short sides of length w. It is centered inside the larger rectangle whose long sides are very very long and whose short sides have length h. You calculate the mutual inductance of the two loops in terms of the given quantities and known constants to see if this could cause the circuit to act abnormally. Because the long sides of the larger rectangle are very long, you decide to neglect the effect of its short sides on the inner rectangle.

A home run is hit in such a way that the baseball just clears a wall 14.0 m high, located 122 m from home plate. The ball is hit at an angle of 37.0° to the horizontal, and air resistance is negligible. (Assume that the ball is hit at a height of 1.0 m above the ground.)

Find the velocity components of the ball when it reaches the wall.

x - component

y- component

1. Identify two situations where CONVEX mirrors are used and explain why.

2. Why is the curved bathroom mirror considered a magnifying mirror. Explain the optics.

3. Why are telescopes made with parabolic mirrors instead of spherical mirrors?

4. Why is a multi-trillion dollar industry dependent on a small critical angle of plastic?( Hint fiber optics).

A psychrometer has a dry-bulb reading of 85°F and a wet-bulb reading of 79°F. Find each of the following measurements.
(a) relative humidity
%

(b) dew point
°F

(c) maximum moisture capacity of the air
gr/ft3

(d) actual moisture content of the air
gr/ft3

A 2.00 mol sample of an ideal gas with a molar specific heat of C_V = (5/2)R always starts at pressure 2.00 ✕ 10⁵ Pa and temperature 300 K. For each of the following processes, determine the final pressure (P_f, in kPa), the final volume (V_f, in L), the final temperature (T_f, in K), the change in internal energy of the gas (ΔE_int, in J), the energy added to the gas by heat (Q, in J), and the work done on the gas (W, in J). (Due to the nature of this problem, do not use rounded intermediate values in your calculations—including answers submitted in WebAssign.)

A.) The gas is heated at constant pressure to 420 K.

P_{f =}
Vf =

Tf=

ΔEint=

Q =

W =

B)The gas is heated at constant volume to 420 K.

P_{f =}
Vf =

Tf=

ΔEint=

Q =

W =

C)The gas is compressed at constant temperature to 250 kPa.

P_{f =}
Vf =

Tf=

ΔEint=

Q =

W =

D)The gas is compressed adiabatically to 250 kPa

P_{f =}
Vf =

Tf=

ΔEint=

Q =

W =

To get a better idea about tidal forces, Esperanza and Mika assume that the black hole is about one solar mass, 2.0 ✕ 10³⁰ kg, and that the distance from its center to the person's feet is 3 km (the approximate Schwarzschild radius, the distance at which the escape speed from the body becomes c, the speed of light). They also assume that the person's mass is 60 kg and the person's height is 2 m. How can they use the equation for the tidal force,  

F_tidal = GMm (1/d^2 - 1/ (d+h)^2) to find how many times greater this tidal force is than the weight of the person on Earth, approximately 600 N? (Choose the ratio of the tidal force to the weight of the person on Earth.)

The closest known star to our solar system is Alpha Centauri, which is approximately 4.30 light years away. Spaceship A, with a constant speed of 0.800c relative to the Earth and a proper length of 100 m, travels from Earth to this star. Spaceship B with a constant speed of 0.600c relative to the Earth travels from Earth to this star.
(a) How much time would elapse during Spaceship A’s trip on a clock on Earth?

(b) How much time would elapse during Spaceship A’s trip on a clock on Spaceship B?

(c) How long is Spaceship A for an observer at rest on Spaceship B

A potter's wheel (a thick stone disk with radius 0.45 m and mass 85 kg) is freely rotating at 52 rev/min. The potter can stop the wheel in 6.3 seconds by pressing a wet rag against the rim and exerting a radially inward force of 85 N. What is the coefficient of kinetic friction between the rag and the wheel?

The Correct answer is 0.19 please explain and show in why?

You have a spacecraft that is capable of reaching a speed of 0.99c and desire to travel to Vega, a nearby star about 25 light years away. In order to keep track of your position, your spacecraft sends out a flash of light every second (by your ship’s clock) during the journey that can be picked up on Earth. In addition, the Earth sends out a flash every second (by the Earth clock) that you can see with a telescope on your ship.

Thus equipped, you depart to your destination, where after arrival you send a radio signal to Earth saying that you have arrived. After spending 0.5 years there, you send a second radio signal that says you are departing to return to Earth.

In answering the following questions, Ignore the negligible time it takes to accelerate and decelerate your spacecraft, and assume Earth and Alpha Centauri have negligible relative motion (compared to the speed of light!):

(a) On the outward journey, what is the frequency of flashes seen coming from your spacecraft back on Earth? Similarly, what is the frequency of flashes you see coming from Earth?

(b) After getting up to 0.99c, how far away does Vega appear to you at the start of the journey? How many years does it take to get there according to your spacecraft clock?

(c) How many years (on the Earth’s clock) after you left Earth will they receive the radio signal that you have arrived?

(d) While you are at Vega, what is the frequency of the flashes the Earth sees from your spacecraft? What is the frequency you see from the Earth’s flasher?

(e) What is the frequency of the Earth’s flasher you see on the way back? What is the frequency of your flasher as seen by the Earth?

(f) How many years after you left (by the Earth’s clock) will the Earth receive the signal that you have started back?

(g) How many years after you left (by the Earth’s clock) will have elapsed when you get back? How much older will you be?

A hollow sphere is rolling along a horizontal floor at 4.80 m/s when it comes to a 26.0° incline. How far up the incline does it roll before reversing direction?

The correct answer 4.47 please explain why and show work?

Determine the power efficiency of the transformer

Three dimensions. Three point particles are fixed in place in an xyz coordinate system. Particle A, at the origin, has mass m_A. Particle B, at xyz coordinates (3.00d, 2.00d, 4.00d), has mass 3.00m_A, and particle C, at coordinates (–3.00d, 3.00d, –2.00d), has mass 3.00m_A. A fourth particle D, with mass 3.00m_A, is to be placed near the other particles. If distance d = 9.90 m, at what (a) x, (b) y, and (c) z coordinate should D be placed so that the net gravitational force on A from B, C, and D is zero?

I need the answer in meters. Also, I already asked and someone ended up getting 0 for part a, -16.5 for part b and 22.9 for part c; none of those are correct. thanks

What is the relationship between the amount of charge of the fixed and test particles and the velocity of the test particle as it moves away from or towards the fixed charge? What implications do these results have in the design of modern technology? How do we use this knowledge in everyday applications?