A 15kg block of frozen water is being acted upon by two forces as shown. Which of the following
diagrams will have the smallest net acceleration?
A)
F2=10N
F =28N
B)
F=100N
Fi=90N
0)
Fi=4N
F2=12N
D)
Fi=150N
F2=140N

Aperson walks first at a constant speed of 4.89 m/s along a straight line from point a to point b and then back along the line from b to a at a constant speed of 2.95 m/s. what is the average speed over the entire trip?

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.

By what primary heat transfer mechanism does the sun warm the earth?