A worker is lifting boxes of identical weight from the ground onto a moving belt. at first it takes him 2 s later in the day it takes him 3 s which statement is correct A) later in the day less work is done in lifting each box.

B) later in the day more work is done in lifting each box

C) later in the day less power Is developed in lifting each box

D) later in the day more power is developed in lifting each box​

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