A train rolls at a constant speed of 10 m/s across a horizontal track. A child standing on the flatbed of the train throws a ball so that it appears to move straight up to an observer standing next to the track. a. What is the horizontal speed of the ball relative to the observer?

Explanation:

Given that the child is in the train, and that the train is moving at a speed of 10m/s, and also the child is standing on the flatbed, hence the child is not moving, therefore the velocity of the child is 10m/s relative to the observer

Also, when the child throws the ball horizontally relative to the observer the horizontal speed is also 10m/s.

therefore the speed of the ball is also 10m/s to the observer

the five characteristics of adolescence are biological growth and development, and undefined status, increased decision making, increased pressure and the search of self.