Aracecar beginning at rest accelerates at a rate of 4.0 m/s2. it takes the car 21s to reach the end of the track. how long is the track in kilometers?

Acombination reaction is when two or more combine to form one product. a decomposition reaction is when a substance breaks down into two or more simpler substances in a chemical reaction.

Imagine that someone pushes one marble toward a motionless marble. would there still be action-reaction forces involved in the collision? how might the marbles’ motions be changed? ?

J. j. thomson’s experiment disproved the theory that an atom