A block of mass 2 kg slides on a frictionless loop the looped track. The block is released from a height of 3.7 m. The looped track has a radius of 0.8 m. (A) What speed does the block have at the bottom of the loop?
(B.) What speed does the block have at the top of the loop?
(C.) What Normal force does the block experience at the top of the loop?
(D.) What minimum height above the ground must the block be placed to make it around the loop without it falling?

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.