Which sentence best describes how the Earth's densest elements ended up comprising the core. A
The lightest elements tended to float to the exterior forming the crust.

B
The densest elements tended to drift to the center forming the core.

C
The lightest elements floated to the exterior forming the crust and the densest element drifted towards the center forming the core.

D
None of the above.

Astudent pushes a 60-n block across the floor for a distance of 10 m. how much work was done to move the block

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

Positive ions differ from neutral atoms in that