From the perspective of a friend stationary on the ground watching a train pass, what path does a ball tossed straight up by a passenger trace?

Answer

An arc (moving both vertically and horizontally)

To the stationary observer, the ball inherits the horizontal velocity of the train while also moving vertically due to the toss, resulting in an arc shape.

From the perspective of a friend stationary on the ground watching a train pass, what path does a ball tossed straight up by a passenger trace?

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