Lisa places a beaker of ice water on a hot plate and measures the temp of the ice water to be 0c. she turns on the hot plate and observes the ice began to melt. when half of the ice is melted she measures the temp again. which of the following is most likely? a) the temp is staying at 0c b) the temp has increased to 20c c) the temp has decreased to -20c d) the particles have stopped moving and she is unable to measure any temp

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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