To decide who pays for lunch, a passenger on a moving train tosses a coin straight upward with an initial speed of 5.25 m/s and catches it again when it returns to its initial level. From the point of view of the passenger, then, the coin's initial velocity is (5.25 m/s)ŷ. The train's velocity relative to the ground is (12.1 m/s) x̂.

(a) What is the minimum speed of the coin relative to the ground during its flight? At what point in the coin's flight does this minimum speed occur? Explain.

(b) Find the initial speed and direction of the coin as seen by an observer on the ground.

(c) Use the expression for ymax derived in Example 4-14 to calculate the maximum height of the coin, as seen by an observer on the ground.

(d) What is the maximum height of the coin from the point of view of the passenger, who sees only one-dimensional motion?