How do eye glasses work BUT first lets

How do eye glasses work?

BUT first, let’s review! l What is energy? l l Can energy be created? l l no or destroyed, it can only be transformed from one form into another What is kinetic energy? l l The capacity for doing work (or to produce heat) (KE) refers to the energy associated with the motion of an object. What is potential energy? l An object can store energy as the result of its position

l What is a transverse wave? l l l What is a longitudinal wave? l The particles of the medium vibrate back and forth along the path that the wave moves. What is the equation to find velocity? l l A wave in which the particles of the medium move perpendicularly to the direction the wave is traveling. V= λ * f What are EM waves? l They are Transverse waves without a medium. They travel as vibrations in electrical and magnetic fields.

l List the EM Spectrum from longest wavelength to shortest. l l What is the speed of light? l l Angle of incidence = Angle of reflection What is refraction? l l 3. 0 X 10^8 m/s What is the law of reflection? l l Radio, Microwave, Infrared, Visible, UV, X-Ray, and Gamma The bending of a wave as it passes at an angle from one substance to another What is diffraction? l Bending of light around a barrier or small opening

Lenses: How do they work? l Lens l Transparent piece of glass or plastic that refracts light in a predictable way

Diverging/Concave lens l A concave lens causes light to diverge, or spread out, making a smaller image Concave Lens

Convex Lens l A convex lens causes light to converge, or focus, the type of image formed by a convex lens depends on the position of the object in relation to the focal point. Notice, that was what up is down and what was down is up after the focal point

Essential Knowledge, Skills, and Processes l Identify some common optical tools, and describe whether each has lenses, mirrors, and/or prisms in it. These should include: l l l eyeglasses flashlights cameras binoculars microscopes

Essential Knowledge, Skills, and Processes l Eyeglasses: have lenses No correction needed a. Normal eye b. Myopia (nearsightedness) Corrected with concave lens c. Hyperopia (farsightedness) Corrected with convex lens

Essential Knowledge, Skills, and Processes l Flashlight: has lenses and a mirror

Essential Knowledge, Skills, and Processes l Cameras: have lenses, mirrors, and a prism

Essential Knowledge, Skills, and Processes l Binoculars: have lenses and prisms

Essential Knowledge, Skills, and Processes l Microscope: has lenses

How have humans used science to engineer technologies that use electromagnetic energy? l l 1. Use of lasers Laser: l l Powerful energy of light due to concentrating one wavelength (frequency)(color) of light All energy is lined up

Lasers On “same wavelength” In sync with one another (laser) Flashlight

Lasers l Uses: l l Fiber optics Surgery UPC codes Burning and reading CD’s, DVD’s & optical flash drives