The diagram below shows the position of the center-of-mass of Christine vs. time, recorded with a webcam while she performs a standing jump into the air. Her feet land back in the spot they left. She is stationary before and after the jump, which starts at point A.

Give the times during takeoff and landing at which her velocity is zero.

0.55 0.50 0.45 0.40 0.35 0.30 0.25 0.20 0.15 0.10 1.2 1.4 1.6 1.8 2.0 2.2 2.4 2.6 2.8 3.0 Time (s) Y (m)