I have a question that I would like to ask here since I'm not an expert or any near to that. Actually I just came up with this question when I was watching The fabric of cosmos. I couldn't find where I can ask this kind of question. So hopefully this is the right place.

What is the "background" of multiverse?

Let me elaborate a little more what that means clearly. As far as I understand, multiverse is a cluster of many universe and it seems like (well from what I saw in documentary) that bubbles in a cup of soda.

What I am curious is that then what is the mechanism of the background or surrounding, I should say, of the multiverse? Since if multiverse "exists" somewhere, then that means the surrounding has to have some kind of characteristics, such as space-time.

I hope that I explained comprehensibly, and somebody can give some reasonable explanation. Even better, any book recommendation would be appreciated!

Even though I studied physics for 1 year and half, I forgot many of them except curiosity. ;)

2. The atmospheric pressure at the sea level is greater than the atmospheric pressure at the mountain top (T,F)

A baseball thrown at an angle of 65.0 ∘ above the horizontal strikes a building 18.0 m away at a point 8.00 m above the point from which it is thrown. Ignore air resistance.

A. Find the magnitude of the initial velocity of the baseball (the velocity with which the baseball is thrown).

B.Find the magnitude of the velocity of the baseball just before it strikes the building.

C.Find the direction of the velocity of the baseball just before it strikes the building.

1. show that critical damping provides the quickest approach to zero amplitude. With less damping (“underdamping”), it reaches the zero position more quickly, but oscillates around it

Please explain in detail

A horizontal pipe carries a smoothly flowing liquid with density 1.39 × 103 kg/m3. At locations 1 and 2 along the pipe the diameters are 5.23 cm and 2.19 cm, respectively. The flow speed at location 1 is 1.79 m/s. What is the pressure difference between location 2 and location 1 (including its sign)? Ignore viscosity.

A hockey player is standing on his skates on a frozen pond when an opposing player, moving with a uniform speed of 2.0 m/s, skates by with the puck. After 2.60 s, the first player makes up his mind to chase his opponent. If he accelerates uniformly at 0.36 m/s², determine each of the following.

(a) How long does it take him to catch his opponent? (Assume the player with the puck remains in motion at constant speed.)
                     s

(b) How far has he traveled in that time?
                       m

You have two glasses of water each with equal amount of it. In glass “A” the temperature of the water is 10 ◦C. In glass “B” the temperature of the water is 30 ◦C. (4/20 credits)
a) The water in glass A has more internal energy

b) The water in glass B has more internal energy c) They have equal amount of internal energy

What formula did you use to derive your answer?

If you're writing about a theory with Yang-Mills/Gauge fields for an arbitrary reductive gauge group coupled to arbitrary matter fields in some representation, is it best to call it a Yang-Mills theory or a Gauge theory?

I've heard that one is more likely to refer to a theory with no matter sector - but I can't remember which one! Or are the terms basically interchangeable in the context of quantum field theory?

A rocket is launched at an angle of 53.0° above the horizontal with an initial speed of 98 m/s. The rocket moves for 3.00 s along its initial line of motion with an acceleration of 31.0 m/s2. At this time, its engines fail and the rocket proceeds to move as a projectile.

(a) Find the maximum altitude reached by the rocket.

(b) Find its total time of flight.

(c) Find its horizontal range.

EXPLAIN ANSWERS PLEASE THE FIRST PERSON I ASKED BEFORE GOT IT WRONG

Optical fibers use reflection to guide light through a channel. Explain, in your own words, how optical fibers are made in order for the light to be reflected off the cladding instead of refracted into it?

A 30.0?F capacitor is charged to 210?C and then connected across the ends of a 4.20mH inductor.

A.Find the maximum current in the inductor.

B.At the instant the current in the inductor is maximal, how much charge is on the capacitor plates?

2. Heat added to a substance goes partly into the translational kinetic energy of its molecules, which directly elevates temperature. For some substances, large proportions of heat also go into vibrations and rotations of the molecules. Discuss whether you’d expect materials in which a lot of energy goes into non-translational molecular motions to have a high or low specific heat capacity?

The two stars in a certain binary star system move in circular orbits. The first star, Alpha, has an orbital speed of 36.0km/s. The second star, Beta, has an orbital speed of 12.0km/s. The orbital period is 137d.

What is the mass of the star Alpha?

What is the mass of the star Beta?

One of the best candidates for a black hole is found in the binary system called A0620-0090. The two objects in the binary system are an orange star, V616 Monocerotis, and a compact object believed to be a black hole. The orbital period of A0620-0090 is 7.75hours, the mass of V616 Monocerotis is estimated to be 0.67 times the mass of the sun, and the mass of the black hole is estimated to be 3.8times the mass of the sun. Assuming that the orbits are circular, find the radius of the orbit of the orange star.

Find the radius of the orbit of the black hole.

Find the orbital speed of the orange star.

Find the orbital speed of the black hole.

Two in-phase loudspeakers are located at (x, y) coordinates (-2.5 m, +2.0 m) and (-2.5 m, -2.0 m). They emit identical sound waves with a 2.5 m wavelength and amplitude a. Determine the amplitude of the sound at the five positions on the y-axis (x = 0) with y = 0.0 m, 0.5 m, 1.5 m, and 2.0 m.