In a "worst-case" design scenario, a 2000-{\rm kg} elevator with broken cables is falling at 4.00{\rm m/s} when it first contacts a cushioning spring at thebottom of the shaft. the spring is supposed to stop the elevator, compressing 2.00 {\rm m} as it does so. during the motion a safety clampapplies a constant 17000-{\rm n} frictional force to the elevator.1. what is the speed of the elevator after it has moveddownward 1.00 {\rm m} from the point where it first contacts aspring? 2. when the elevator is 1.00 {\rm m} below point where it first contacts a spring, whatis its acceleration?

Cells in the nervous system have a potential difference of 70 mv across the cell membrane separating the interior of the cell from the extracellular fluid. this potential difference is maintained by ion pumps that move charged ions across the membrane. is this an emf? select the correct answer and explanation. 1)no. the ion pumps cannot separate charges; thus, they cannot create a potential difference. 2)yes. the ion pumps cannot separate charges, but they still can create a potential difference. 3)yes. the ion pumps can actively separate charge; thus, they can create a potential difference. 4)no. the ion pumps can separate charges, but they cannot create a potential difference.