Which of the following is not non constant force A. gravitational force
B. frictional force
C. magnetic force
D. electrical force

Frictional force. hope this helps have a good day

frictional force

Explanation:

Friction always acts to oppose any relative motion between surfaces. For the simple example of a book resting on a flat table, the frictional force is zero. There is no force trying to move the book across the table, so there is no need for a frictional force because there is nothing for the frictional force to oppose.

the word that best describes martin luther king jr.'s tone in the video is dignified

martin luther king, jr. was a social activist and baptist minister who played a key role in the american civil rights movement from the mid-1950s until his assassination in 1968. the video shows his manner and attitude having or showing a composed or serious manner that is worthy of respect so dignified is the correct answer

c) up is the direction the magnetic force is acting on the charge.