[填空题]
A person jumps off ata5rqp hbr.p:/+r ei/ diving board 4.0 m above the waterr6m9: udrh-zb ’s surface into a deep pool. The person’s downward motion stops 2.mr:r6 9h-buz d0 m below the surface of the water. Estimate the average deceleration of the person while under the water. $\approx$ $m/s^2$ (Round to the nearest integer)
