When the stand on which w rests is shaken, a multiplied representation of this movement takes place at h, and any small body resting on that point, as for example a small screw s standing on its head, may be caused to topple over.
Acting as the stand so the unit does topple over is a large 6 watt subwoofer speaker that folds down away from the PSP.
Which you almost do, until Harry runs forward prematurely, causing the plane to topple over the edge !
The umbrella can be considerably shorter and lighter than one you would need to plant in the sand, and far less likely to topple over or blow away.
