consider a runner in lane 1 with a speed v1 and a runner in lane 4 with a speed v4, where the ratio of the speeds v4/v1 is 2. the radius of lane 4 is b times the radius of lane 1, and both runners have the same mass. which of the following claims is correct about the net forces f1 and f4 exerted on the runners in lanes 1 and 4, respectively?

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.