Two forces 10 N and 15 N are pushed to a box. In which of the following situations would the combination of the two forces produce the greatest magnitude of the resultant? When two people push the box to the same direction.
One person pushes to the left, and other person pushes to the right.
One person pushes up, and other person pushes to the right.
One person pushes to the left, and other person pushes down.

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