According to Newton’s first law of motion, which of the following objects will change its motion? A. A train pulling on another train, each with the same amount of force.
B. A bike rider on a smooth and level road, pedaling at a constant rate.
C. A chair sitting on the floor with balanced forces acting in opposite directions.
D. A ball rolling across the floor with friction acting in the opposite direction.
A ball rolling across the floor with friction acting in the opposite direction.

D.

Explanation:

the friction will cause the ball to stop moving which is a change

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

prndulum needs thread, weight clock to time swings