Cds and dvds act effectively like diffraction gratings when reflecting laser light. holding the disks 1.2 from a wall, you notice that the difference between the two = 1 bright fringes is 98 for the cd and 210 for the dvd when red laser light ( = 650 ) is reflected. how many more lines per mm does a dvd have than a cd?

Find the vertex(use the completing the square method), findthe x- and y-intercepts, and sketch the graph offunction. y = 2x2 + 4x - 1

Which is an example of gaining a static charge by conduction? a) rubbing a balloon against your hair. b) shuffling your shoes across a carpet. c) bringing a charged rod near an electroscope. d) touching your car on a cold day and getting a shock.

Very large accelerations can injure the body, especially if they last for a considerable length of time. one model used to gauge the likelihood of injury is the severity index ( ), defined as =/ . in the expression, is the duration of the accleration, but is not equal to the acceleration. rather, is a dimensionless constant that = the number of multiples of that the acceleration is equal to. in one set of studies of rear-end collisions, a person's velocity increases by 13.7 km/h with an acceleration of 36.0 m/s2 . let the + direction point in the direction the car is traveling. what is the severity index for the collision?