The starting amount of radioactive iodine-131 was 250 g. the half-life is 8 days. when leslie measured the amount, she
measured 15.625 g of radioactive iodine. how many days have elapsed between measurements?

The pressure proportional to the area a- inversely b- directly c- increase d-decrease

True or false graphs must include scales that increase by the same amount

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