Ultrasound waves rays energy( waves, rays, energy ) are partially reflected totally internally reflected refracted diffracted partially refracted( partially reflected, totally internally reflected, refracted, diffracted, partially refracted ) when they meet a boundary between two different media substances places elements( media, substances, places, elements ). The time taken for speed of distance taken by( time taken for, speed of, distance taken by ) the reflections refractions diffractions( reflections, refractions, diffractions ) to reach a detector can be used to determine how far away much time away quick( far away, much time away, quick ) that boundary is.

Fill in the blanks about the safety and image quality of X-rays and ultrasound.

SAFETY:
Ultrasound X-rays CT scans( Ultrasound, X-rays, CT scans ) is non-ionising ionising high-frequency( non-ionising, ionising, high-frequency ) and safe dangerous dangerous in large quantities( safe, dangerous, dangerous in large quantities ). They can cannot( can, cannot ) be used on babies.
X-rays Ultrasound CT scans( X-rays, Ultrasound, CT scans ) are ionising non-ionising high-frequency( ionising, non-ionising, high-frequency ), and can cause genetic mutations injuries viruses bacterial infections( genetic mutations, injuries, viruses, bacterial infections ) which harm cells the immune system humans nuclei( cells, the immune system, humans, nuclei ). They cannot can( cannot, can ) be used on babies.
CT scans use more less the same amount of( more, less, the same amount of ) X-rays ultrasound waves ionising radiation infrared radiation( X-rays, ultrasound waves, ionising radiation, infrared radiation ), so are more less simliarly( more, less, simliarly ) ionising. They increase decrease maintain( increase, decrease, maintain ) the radiation dose potential damage ionisation( radiation dose, potential damage, ionisation ) even more. They cannot can( cannot, can ) be used on babies.

IMAGE QUALITY:
Ultrasound X-rays CT scans( Ultrasound, X-rays, CT scans ) images are usually fuzzy. clear. three-dimensional.( fuzzy., clear., three-dimensional. )
X-ray Ultrasound CT scans( X-ray, Ultrasound, CT scans ) images are clear fuzzy( clear, fuzzy ) if showing bone or metal bone or tissue muscle or tissue metal or muscle tissue or metal( bone or metal, bone or tissue, muscle or tissue, metal or muscle, tissue or metal ) - otherwise, they are fuzzy clear( fuzzy, clear ).
CT scans are clear, three-dimensional two-dimensional 360 degrees expensive( three-dimensional, two-dimensional, 360 degrees, expensive ) and high-resolution expensive low-resolution fuzzy( high-resolution, expensive, low-resolution, fuzzy ). They can be used to diagnose complicated illnesses common illnesses complicated surgery common surgery sexually-transmitted infections( complicated illnesses, common illnesses, complicated surgery, common surgery, sexually-transmitted infections ).

Explain how refraction occurs at a boundary.

1) The ray of light X-ray electromagnetic wave ultrasound wave( ray of light, X-ray, electromagnetic wave, ultrasound wave ) reaches a boundary between two different media. mediums. substances. atoms.( media., mediums., substances., atoms. )
2) One side of the ray wave particle( ray, wave, particle ) hits the particles atoms elements substances( particles, atoms, elements, substances ) of a different density size speed volume( density, size, speed, volume ) first.
3) This causes that side to either slow down stop turn( slow down, stop, turn ) or speed up slow down stop turn( speed up, slow down, stop, turn ).
4) This causes the light ray X-ray ultrasound electromagnetic wave( light ray, X-ray, ultrasound, electromagnetic wave ) to turn.

REFRACTIVE INDEX - The speed rate velocity time( speed, rate, velocity, time ) at which light travels passes is refracted is reflected is diffracted( travels, passes, is refracted, is reflected, is diffracted ) through a medium material boundary( medium, material, boundary ).

The higher lower( higher, lower ) the refractive index refraction rate density level of attraction between the atoms particle density( refractive index, refraction rate, density, level of attraction between the atoms, particle density ) of a given material, the lower higher( lower, higher ) the critical angle angle of incidence angle of refraction angle of reflection total internal reflection refractive index( critical angle, angle of incidence, angle of refraction, angle of reflection, total internal reflection, refractive index ) of the material.

Give the four main ways that lasers can be used.

- Lasers can be used in surgery to cut through body tissue bone organs muscle individual cells( body tissue, bone, organs, muscle, individual cells ).
- Lasers cauterise pierce disinfect burn( cauterise, pierce, disinfect, burn ) (burn and seal shut) small blood vessels as they cut through the tissue.
- Lasers can treat skin hair tissue organ heart( skin, hair, tissue, organ, heart ) conditions such as acne scars. kidney failure. heart attacks. strokes. pulmonary embolisms. fractures.( acne scars., kidney failure., heart attacks., strokes., pulmonary embolisms., fractures. )
- Lasers are used in laser eye chiropractic general heart transplant kidney transplant laser( laser eye, chiropractic, general, heart transplant, kidney transplant, laser ) surgery.