An electric winch pulls an 875 N crate up a 15° incline at 0.25 m/s. The coefficient of friction between the
crate and incline is 0.45.
a. What power does the winch develop?
b. How much electrical power must be delivered to
the winch if it is 85 percent efficient?
Please someone help...?

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.