`Physics at the ZooPeter Insley                   Retired                           Objective:     The idea is to try to answer some physics questions at the zoo.  The teacher can adjust the level of these questions to almost any grade, or just skip questions that are inappropriate.  No materials or apparatus is necessary.  We used Lincoln Park Zoo in Chicago.1.  Sizes     Animals are physically designed by evolution to function well.  Compare the width of the legs of large heavy animals with the width of a similar small animal.  Which animals did you compare and what did you find out?     Now compare faster and slower animals, and see how the legs compare to the body.  Which animals did you choose, and what did you find out?     Now compare the weight of an animal with the weight of food consumed each day.  Food is necessary for energy, and that energy is mostly used to produce heat and keep the body warm.  Heat is lost from the surface, and small animals lose heat more rapidly because they have more surface compared to their weight. (Divide the surface area by the weight to calculate the factor).  Compare the animals you have chosen here.2.  Center of Gravity     Look at various animals and estimate where their center of gravity (or balancing point) is.  If the center of gravity is not supported by the animal's legs, the animal will fall over.  Look at a giraffe, a peacock, an elephant, and a large deer.  How do these animals support their center of gravity when they walk and lift a leg or two off the ground?  Tell what animals you watched and what you observed.     Look at a pregnant animal and then look at a pregnant woman.  How does being pregnant change how they walk?  Think about the center of gravity.3.  Estimation     Estimate the weight of various animals, and then look at the plaques and see if they tell you the answer.  Which animals did you choose, and how close was your guess?  Many people estimate far too high for the American Eagle.  Ask the zoo personnel how much an eagle weighs.4.  How Animals Travel     Every animal has to "push off" or exert a force in order to move.  Think of snakes and birds.  What do they push against?  How many hooves are on the ground when a deer pushes off?  What did you observe?     Sketch a distance time graph for a monkey or a snake.5.  Archimedes Principle (or Sinking and Floating)     How do turtles, snakes, or Polar bears sink and then rise again?6.  Paddle Boat     There are paddle boats for rent in the lagoon by the restaurant.  How much do they sink when a person walks into them?  What do they push against?  Estimate how fast you can go in the boat, and compare that with how fast you can walk.  Why does the boat float if it is made of metal?7.  Light in the Water     Find one of the tanks where you can see a bear or seal swimming under water.  Look up at the surface.  Can you see out, or do you see a reflection?  Is your vision distorted when you look directly into the tank?  How far can you see?8.  How Do Animals Fall?     Look at the monkey and the flying squirrel.  How do they use the air to affect their fall?  How does a bird do it?9.  Sound     Which animals have the highest and lowest pitched sounds?  What about bats?  How do they produce such a high pitched sound?  Why are sounds under water dangerous to the animals?  (So you shouldn't tap on the glass!)10.  Do One Yourself     I hope my questions gave you paws.  Now it's your turn.  Think about your presentation this summer.  Where did you see an application of your lesson at the zoo today?           `