Tunnels

Hey there my dedicated followers! Its been a five day weekend and now I'm officially a second semester senior and done with college apps! Hello senioritis!!!!! So during this looong weekend I went to a beachhouse in laie with some friends. I realized why we're all so lucky to live in Hawaii and also why physics is sooo cool! I mean check this tunnel I made. Only with AP Physics would I be able to understand why the tunnel remains a tunnel and doesnt cave in. (by the way, the tunnel im referring to the little hole at the bottom of the picture) So you wanna know why?? Well it's simple, the weight of the sand above the tunnel is supported by the normal force of all the sand surrounding it. This is why its better to construct sand castles (or tunnels) with wet sand, because water acts as glue for the substance, sand. The water holds together the sand which creates a greater normal force than the weight from the sand above the tunnel. Also the compactedness of the sand is how it stay in a tunnel form. So, go make a tunnel at the beach to see for yourself!