What fraction of the original number of nuclei present in a sample will remain after (a) 2 half-lives; (b) 4 half-lives; (c) 10 half-lives?

How would a small bar magnet be oriented when placed at position x?

In an old-fashioned amusement park ride, passengers stand inside a 3.0-m-tall, 5.0-m-diameter hollow steel cylinder with their backs against the wall. the cylinder begins to rotate about a vertical axis. then the floor on which the passengers are standing suddenly drops away! if all goes well, the passengers will “stick” to the wall and not slide. clothing has a static coefficient of friction against steel in the range 0.60 to 1.0 and a kinetic coefficient in the range 0.40 to 0.70. part a what is the minimum rotational frequency, in rpm, for which the ride is safe? express your answer using two significant figures. f f = rpm

Ais a multilevel way of grouping items based on common properties among them. a. memory b. conceptual hierarchy c. schema d. semantic network