My question is little bit philosophical. I would like to explain my ideas with a 2 dimensional universe model.

If we had lived in 2 dimensional universe like a plane, What could we observe when seeing a 3d object?

For example: If a square pyramid that is inside full of material comes to the plane universe in right angle, what could the people who live in 2d universe observe? Firstly, we could see small square and slowly it would enlarge and then it would dissappear suddenly. If the scientists who live in the 2d universe observed such event , All scientists could get shocked and they could check their physics formulas because energy is not conversed in that event. They had believed that Energy is conserved and nobody could create energy from nothing and finally they could understand that total observed universe energy can be much more what they calculated with their formulas.

My questions:

What could we see a 4d pyramid comes to our 3d universe? is it correct that Firstly we would see small cube and it would enlarge and then suddenly disappears?

Dark matter and Dark energy is related with such ideas? http://map.gsfc.nasa.gov/universe/uni_matter.html

I know we do not observe such strange events till now but maybe scientists can get some results during micro experiments. Is there any such experimental results at least in micro universe (atomic level experiments in quantum mechanics)?

Sorry for your time if it was asked before.

Two positive charges of 1.5e-10 C are placed on the x axis at distances +12 cm and -12 cm from the origin, respectively. A third positive charge of 5e-11 C can be moved along the y axis. At what value of y the electrostatic force on the third charge is maximal?

A tennis player hits a ball 2.0 m above the ground. The ball leaves his racquet with a speed of 16.0m/s at an angle 4.5? above the horizontal. The horizontal distance to the net is 7.0 m, and the net is 1.0 m high.

By how much?

Kindly answer both questions 1 abd 2 fully.

Question 1) Find the dispersion relation for one dimensional diatomic lattice?
(definition and difference of optical branch and acoustical branch)

Question 2) Find the displacement u(x,t) for one dimensional diatomic lattice?

Kindly answer both questions 1 abd 2 fully.

Consider a rock that is thrown off a bridge of height 85 m at an angle ? = 23

True or False , explain why

Light travels faster in vacuum than it does in a glass.

When light enters a medium with a higher index of refraction, the ray is bent farther away from the line normal to the boundary.

The path of a ray of light between two points is the path that minimizes the travel time.

White light that is reflected from a surface will be separated into a visible spectrum.

If one stands by a swimming pool, a person standing in the pool will seem to have long legs.

The cosmic microwave background (CMB) matches a 2.7 K blackbody spectrum extremely well. For a space telescope observing the CMB with an efficient detector with a collecting area of 0.01 m2, estimate (i) the wavelength at which the CMB peaks in intensity, (ii) the power in watts of CMB photons collected by the detector and (iii) the number of CMB photons per unit volume in the vicinity of the space telescope.

A woman can read the large print in a newspaper only when it is at a distance of 62 cm or more from her eyes. (a) Is she nearsighted (myopic) or farsighted (hyperopic), and what kind of lens is used in her glasses to correct her eyesight? (b) What should be the refractive power (in diopters) of her glasses (worn 2.9 cm from the eyes), so she can read the newspaper at a distance of 29 cm from the eyes?

A: I know she's farsighted

B: I did (1/ 29-2.9 + 1/(62-2.9) = .05523 x 100 = 5.52 cm, which was wrong. How do I solve this part of the equation?

3. A ski jumper starts from the top of a frictionless track making a 60° angle with the ground. The starting point is 25.0-m above the ground, and the jumper is launched from the upturned end of the track 3.00-m above the ground at an angle of 60°.

a) What is her speed as she leaves the jump?

b) How far away from the track does the jumper land?

at the same diameter, an air bubble rises faster in liquid faster than a sand pebble falls in liquid water. The densities of air water and sand are 1.2,1000,2500 kg/M3 respectively.

Answer True of False whether or not the air buble travels faster. Need help don't understand the theory behind this question

The discovery of the constant speed of light proved that classical physics was unable to explain more advanced scientific concepts and led to the birth of a new field—modern physics. The Michelson-Morley experiment proved that light moves at a constant speed at all times, regardless of the relative speed of the observer. Discuss why this characteristic makes light unique compared to all other moving objects in the universe. Support your reasoning with at least two concrete examples of other moving object

What wavelength monochromatic source in the visible region (390 to 710 nm) can be used to constructively reflect off a soap film (n = 1.46) if the film is 77 nm thick?

Two stars 19 light-years away are barely resolved by a 63 cm (mirror diameter) telescope. 1ly=9.461×1015m.How far apart are the stars? Assume λ = 550 nm and that the resolution is limited by diffraction.

d=_____? m

A lens system consists of two lenses 14.0 cm apart. The first lens is convex (converging) and has a focal length of 6.72 cm. An object is placed 3.29 cm in front of the first lens and produces an image 7.00 cm behind the second lens.
Q1:What is the focal length of the second lens?
A:5.215 cm

Q2:What is the magnification of the final image?

A2:

Please provide A2 and show all work, I already have the correct answer to Q1(5.215cm)

Why do some gradients change frequencu while others change phase in MRI?