Anarrow beam of light from a laser travels through air (n = 1.00) and strikes the surface of the water (n = 1.33) in a lake at point a. the angle of incidence is 58 degrees. the depth of the lake is 2.9 m. on the flat lake-bottom is point b, directly below point a. (a) if refraction did not occur, how far away from point b would the laser beam strike the lakebottom? (b) considering refraction, how far away from point b would the laser beam strike the lake-bottom?

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.