If Keiji stands at the bottom of a pool and Aamina stands outside the pool at the pool's edge, what difference will they notice when they both press their palms against the water's surface? Respond very briefly.
Keiji, standing underwater, will feel a greater pressure on his palm compared to Aamina, who is pressing her palm against the surface while standing in the air. This difference in pressure is because water is denser than air and also because the water above Keiji's hand exerts an additional force due to its weight. As a result, the deeper one goes below the water's surface, the greater the pressure exerted by the water above, which Keiji is experiencing at the bottom of the pool. Aamina, being at the edge and pressing her palm just at the surface, is not subject to this additional pressure caused by the weight of the water.