Ben and andy each pushed an empty grocery cart. ben used twice the force, but they both did the same amount of work. explain how this is possible

Air flows upward in the wick of a lantern because of the liquid property called

2kg of refrigerant 134a undergoes a polytropic process in a piston-cylinder assembly from an initial state of saturated vapor at 2 bar to a final state of 12 bar, 80 degree c. a)determine the work for the process in kj. b)sketch the process on a p-v diagram.

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