Starting from rest, a disk rotates about its central axis with constant angular acceleration. in 5.0 s, it rotates 25 rad. during that time, what are the magnitudes of:
(a) the angular acceleration,
(b) what is the instantaneous angular velocity of the disk at the end of the 5.0 s?
(c) the average angular velocity for first 5 s?
(d) with the angular acceleration unchanged, through what additional angle will the disk turn during the next 5.0 s?

Rank the six combinations of electric charges on the basis of the electric force acting on q1. define forces pointing to the right as positive and forces pointing to the left as negative. rank positive forces as larger than negative forces. q1,q2,q3 = positive(+) q1 = + q2 = + q3 = - q1 = + q2= - q3= + q1= - q2= + q3= + q1= + q2= - q3= - q1,q2,q3 = negative

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.

A1.5m wire carries a 2 a current when a potential difference of 52 v is applied. what is the resistance of the wire?