A ballplayer catches a ball 3.0s after throwing it vertically upward. With what speed did he throw it, and what height did it reach?

Answer: 15 m/s and 11m

Question

A ballplayer catches a ball 3.0s after throwing it vertically upward. With what speed did he throw it, and what height did it reach?

Answer: 15 m/s and 11m

anonymous · Answer

the anwer is wrong. :/

turingtest · Answer

The numbers are approximate, but not totally wrong.
At the top v=0 and the time past will be half the total time given, so we have$$v=v_i-gt=0\to v_i=gt\approx10(1.5)=15m/s$$we can use a kinematic to find the height$$s=v_it-\frac12gt^2\approx15(1.5)-10(1.5)^2\frac12\approx11$$