How much impulse is applied by a 25 N force in 30 seconds?

Actually Welcome to the Concept of the Impulse.

Impulse is denoted by 'J'

hence, J = F. dt

so we get as,

J = (25)*(30)

J = 750 N-s

===> hence the impulse is 750 N-s

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