(Solved): At time \( t=0 \), a rock climber acccidentally allows a piton to fall freely from a high point on ...

At time \( t=0 \), a rock climber acccidentally allows a piton to fall freely from a high point on the rock wall to the valley below her. Then, after a short delay, her climbing partner, who is \( 20.0 \mathrm{~m} \) higher on the wall, throws a piton downward. The positions y of the pitons versus time \( t \) during the falling are given in the figure. With what velocity was the second piton thrown? Number Units