Answer Happy

Problem z (from past final exam) The Basilisk Lizard (or sometimes called the Jesus Lizard) is a lizard that can walk across a pond of water without sinking. It is about LL = 0.15 m in size, moves across the water at a velocity V1 = 1 m/s, and scurries so that its feet makes contact with the water at a frequency of ft = 10 s. It is a fascinating creature! water FR The popular TV show "Mythbusters" recently aired a program where they tried to prove or disprove a viral Youtube video that shows a human running across water mimicking this lizard. They did not carry out a dimensional analysis (which would have been very informative) before performing human testing. You can determine the outcome quite easily with such an analysis. Let's say you intend to carry out human-sized (LH= 1.5 m)human-powered model studies of a Jesus Lizard gate across water. Your experience with fluid mechanics tells you that the reaction force generated by the "running" motion across the water, Fr (which must be enough to counteract the specimen's weight for it not to sink) depends on the density (p=10 kg/mº) and surface tension (n=0.1 N/m) of the water, as well as the velocity, V, characteristic size, L, and foot striking frequency f., i.e., FR = (0,1.V.L.D (a) What are the appropriate (dependent and independent) A groups for this problem? (b) What velocity, Vw, and frequency fi, must the human-size and human powered studies be carried out at to maintain dynamic similarity to the lizard motion? Of course, we are assuming that the human powered model is geometrically similar to the lizard. (c) Is the answer to (b) reasonable, i.e., can you see a human initially running onto a pond at this speed and paddling at this frequency? (answer yes or no) (d) The reaction force on this lizard is equal to its weight, which is about Fru=IN. Under conditions of dynamic similarity, what can you expect the reaction force, Fri, on the human-powered model to be?