Answer this question correctly for a pat on the back.

If a star is moving toward earth, it is

Because atoms of elements in the same group of thbecause atoms of elements in the same group of the periodic table have the same number of neutrons, they have similar properties. select the best answer from the choices provided t fe periodic table have the same number of neutrons, they have similar properties. select the best answer from the choices provided t f

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